Regarding cost effectiveness or "return on investment" for these various systems, I'm presenting these as options for folks looking to replace their hot water systems for whatever reason, e.g. replacing a broken or old system, or simply because they want to, I'm not considering the cost implications here, it's up to you to do your own calculations to determine if you feel it's worth it or not. I'll explain my own reasons for doing this in the next video, so look out for that one in the coming few weeks.
Only just came across this channel, loving it already. My biggest draw is that your presentation is not "Stop doing that! do this!" Instead, you're very clear about "Here are some more options for you to consider"
Thank you, I really appreciate your kind words. I absolutely try to not be prescriptive about these things as I know full well that different people have different priorities so I'm glad that comes across. I hope you continue to enjoy the channel.
Indeed. After we got the A2A system I started wondering if such a thing existed and lo and behold they did! There were only two on the market that I could find back then but now I know of at least four, so I'll be covering them all in the next video, comparing the specs.
11:36 - was my way of thinking till yesterday, when Vaillant confirmed, that our aroSTOR's hot water storage cylinder can't be individually serviced, so now that it ruptured, we'll have to dispose of the whole unit - even though the HP is working completely OK (like well, now it's OK, as the compressor had to be changed when the unit passed 18 months service time.)
Dang, that's annoying. We went with the Mixergy iHP which is in two parts, cylinder and HP separate, so with any luck if something similar happens to ours it wouldn't all need replacing. Time will tell, of course, you never know if that would work in practice.
well,@@TimAndKatsGreenWalk, I would maybe use some stronger language, but it is what it is. so my idea now is to go with a Sunamp thermal battery (should be good for 40k cycles, not mentioning it has 10 years of warranty) and hook it up to an air-source heat pump (ASHP) and when we get one installed, a PV system. when and if the ASHP wouldn't be able to produce decent amount of forward going temperature (which can eventually happen here in Hungary) then we still have the grid to feed into the Sunamp. I can't yet think of a more minimalist setup, that involved lesser parts.
Great summary Tim and really useful to see all of this condensed and explained in one video. I installed an ASHP in May which complements my PV system. Working really well and, though expensive, delighted to be free of fossil fuel!
Great video Tim and all the options you mentioned are exactly the same process that I went through prior to my final choice about 3 months ago. The Mixergy by it self seemed a good option as it had some clever way of heating the water just enough for what you actual needed to use but the cost/efficiency ratio for me wasn’t enough to warrant the cost to buy it. They have indeed brought out a ASHP version that sits on the top of the cylinder but I dont think its available yet and from what i understand on pricing it wont be as competitive as other ASHP all in one cylinders. The Sunamp was one that I looked at about 2 years ago and they do look to be efficient for what they do but I felt that they had some major points that put me off, first is the actual weight of them, they are incredible heavy due to the internal heating mixture and just getting it into a house might be an issue especially if you plan on having it upstairs in the traditional location for hot water tanks. They do use much less room but probably the same footprint as a water tank just not as high. I didnt like the fact that I couldn’t obtain clear efficiency rates for what it would cost to charge the full unit and how much hot water it would provide. The other company Fisher - basically use a Sunamp which is rebadged from what I read back when i was looking at them. I decided on an ASHP all in one unit after much research and making sure i had a a hot water replacement for when I replaced my old oil boiler which did my heating and hot water. I went with the same setup for heating the house as you with the Toshiba Haori units and so far they are working out very well. Roll on the cold weather for the real test ! . The ASHP all in one unit I went for in the June of this year was chosen as it was more or less the only one I could easily obtain and at the price point that I was happy with. Installation was easy for my plumber, who had never installed an ASHP water tank previously but it was exactly the same type of water tank install as any other traditional water tank. He did worry about the ASHP part but he didnt have to do anything other than plump it into my existing hot water pipes and the electric. The Air flow is important so the location of these units needs to be able to get two 6 inch airflow pipes out to the outside of your house. The noise of them with the air flowing is minimal but I expect having it located in an upstairs hot water tank cupboard would not be the ideal place. I located my where my old oil based boiler was which was in the garage attached to my house and that gave me one of the air intake holes already due to the old flue for the oil boiler. So far I have seen at least a 50% decrease in my electrical use since installing it compared to heating my old hotwater tank on the electric element only. In summer I expect that rate to become very efficient but as we get colder days now i will reduce but if it saves even 1 kWh per day then its still a saving. I’m looking forward to your next video and to see what you finally went for. (I’ve not mentioned what I’ve got as the setup until after you have made your video) thanks for doing the videos :)
Well, the next video will have a lot of specs comparisons so buckle up! It's good to hear you've had success with your choice and I'm looking forward to getting this sorted next year.
We switched to a heat pump water heater a few months ago and it works well in just heat-pump mode. We can use immersion elements if we somehow need them. If you have the right space and setup for it, it's great.
Another great and informative video, thank you. I am looking into an Air to Air source heat pump but I might cheat and try and get it all sorted in one go, like the new Daikin all in one solution. Though currently I have a combi boiler so need to find space in a modern house which isn’t easy. Looking forward to your next video going into more detail.
Yeah, space for the cylinder is the killer. We're lucky we have room but I can see that being an issue for lots of folks who want to get heat pump heating systems that requires a cylinder for the hot water.
@@TimAndKatsGreenWalk This is the big problem for most smaller properties including flats and apartments. Heat pumps are more efficient, but you can't justify the cost of a powerful heat pump for a small property if you only need the maximum power to heat DHW quickly - low and slow is the heat pump mantra so finding somewhere to fit a water tank is necessary if you want to use a heat pump. I wish that rectangular tanks were more common as these maximise the volume of water stored. It would also be nice if Vaillant did a version of the aroSTOR that could use a remote cylinder, like the Oschner Europa Mini can. Oschner reliability seems to be lower than Vaillant though.
My Eddi uses around 7 to 9 kWh of electricity to heat the DHW cylinder. Havng an ASHP, I found it was 2 to 3 kWh to do the same . For now, the Eddi is triggering a home assistant automation to then turn on the ASHP to heat DHW, when there is sufficient spare solar. You have found some interesting options for those with the air heating system as you have.
Very neat use of the eddi. Not sure what to do with mine once I get a heat pump for the hot water. Might give it away to someone who could make better use of it.
@@TimAndKatsGreenWalk You can use the Eddi to operate the heat pump for the hot water. The Eddi has some neat features to allow it to run the heat pump if there is enough solar pv generation to do so, and to use the immersion heater when there isn't. There is TH-cam video called "The ULTIMATE Solar Heat Pump HACK" on the Artisan Electrics channel that shows this being setup.
Very informative video. We made the conscious choice of cutting down our fossil fuel use and installed PV 3 yrs ago and is a 2 electric car household. I have been waiting to change our 12 yr old veissman when it gives up the ghost and was disappointed when Octopus came and did the survey for a Daikin HP and was told we would need to put the pump in the garden as the regulations didn't allow installation in the side ( due to lack of space, space is premium in manchester suburbia even with large houses). They also wanted us to have absolutely humongous radiators and suggested running the pump at 45C. To top it all the guy who came whispered in my ear to stick with the boiler. My boiler died 2 weeks ago and I am changing to a system boiler (98% efficient Worcester Bosch ) with a tempest single coil HW cylinder hoping to heat the water at night with my cheap IO tariff and surplus PV elec during summer. While i want to reduce my energy use I am also a pragmatist and do not want to spend huge amounts for Sunamp and mixergy like devices. I feel exporting with the new Octopus tariffs does both for me. My only disappointment is sticking with natural gas for heating.
That's fair. They really need to loosen the planning requirements if they're serious about getting people to install heat pumps. It's ridiculous at the moment and it's really holding things back.
@@TimAndKatsGreenWalk My cylinder is going to be 250L, I was under the impression it would need about 4 hrs to heat this up, but was a bit confused about your comment in an earlier video of yours about hot water times 20-30 min twice daily.( 3 tips on reducing gas usage). Are you talking about something else? Also what is your opinion about adding a solar boost to use PV on bright days? Will probably use more of my own energy though will lose money on it with the export tariff being very attractive.
@@sukugeorge67 yeah, that sounds about right. We did only need about 40 mins to heat our hot water when we had the gas boiler (we use between 100 and 150 litres per day), whereas now it takes more like 2 hrs with the immersion heater, because it's less powerful than the gas boiler. A heat pump is also less powerful than a gas boiler so will take longer too. You may find you use less than a full tank each day so will only need to heat back up what you used the day before, which will take less time.
Old immersion tanks used to have 2 heater elements because of economy 7 switched electric. One element was controlled by the grid daily, and the second was used as a boost function if you needed more hot water during peak hours.
Thanks Tim and Kat. I love the fact that i can pretty much find all the information i need on any thing to do with going carbon free on channels like yours excellent excellent excellent. I am at the beginning of my journey into this. My plan is, solar on east-west roof, givenergy all in 1, zeb boiler and mixergy water cylinder. We're on octopus go as we ha an ev, so would use cheap rate over night to charhe zeb when not enough solar, hopefully winter only. Not sold on heat pumps as we have a 1950s bungalow with a double dormer that has micro bore up there. Ps just bought the thermal camera from the link in your video.👍
Nice. Might also be worth keeping your eye on the new Octopus Cosy 6 heat pump that's coming soon, too. That's a "high temperature" HP so might suit you better than the existing ones, as you can drop it in and keep all your existing pipes and rads. And given the boiler upgrade scheme is now £7.5k you might find it's essentially free to install!
I looked into a sunamp before we had all of our system changed. It worked out VERY expensive with an A2W ASHP as it needs to be specced to be high temp. The PCM in the Sunamp needs 60C+ in order to charge. I went with a Mixergy. It can really only be half filled by electric directly. When using the heat pump it needs to be all done. The good thing is it uses an external plate heat exchanger so transfers more of the heat energy to the tank water. Tbh, in hindsight I would have gone for a Mitsubishi cylinder along with our Ecodan and used the Mitsubishi smart controls.
Hindsight is a wonderful thing. We live, we learn, we realise we should have done things differently! Oh well. Sounds like you got a decent solution in the end though.
I live in spain, i put one of those tube systems on my roof terrace 3 years ago. they work great for spain. i found i needed to put one of those electric filaments in the place it stores the water for about 6 weeks in the winter. Now bear in mind that the sun is out here for most of that time about 16c. So not sure how they would work for most of the time in Great Britain.
Yeah, I can imagine it's ideal for Spain. It's definitely viable in the UK over the summer but I expect it'd need more than six weeks of top-up heating over the winter. I'd be interested to hear from anyone in the UK with such a system to share some real world experience.
I've also been looking. I liked the Vaillant aroSTOR a lot - simple local controls which do most of what you need. Option for a voltage free contact to run either heatpump or "backup" resistive heater, so easy to add to home automation and keep everything local. Then mixergy put together their own heatpump integrated cylinder and started throwing mud at the serviceability and limited warranty of the "competition" (Heatpump dies -> new cylinder), but I don't want mixergy as they're asking for too much money for something overly dependent on their cloud service... which put me off both systems, and the gas combi I have now is working (if more carbon intensive than I'd like..) The Daiken looks interesting, previously looked at the Samsung EHS TDM+, but the indoor water unit is huge and won't fit where the old water cylinder was...
@@TimAndKatsGreenWalk While they look cosmetically very different, the control system looks very, very similar to the aroSTOR. Might be the same OEM for the Heatpump?
@@stevescott9289 I'm not sure. I plan on comparing all the specs and data sheets so if they are suspiciously similar then you might be right. I had a feeling they were a bit different though when I first looked.
Hi Tim, we are planning a rather similar air con and heating solution to you, and just to make you feel better about your choice I’ve been told (but I’m no expert) that all the air to air heat pumps available in the UK can’t do water as well, there are ones that do, available in the EU but they haven’t come to us here in the uk it seems.we are planning to upgrade my partners family bungalow, that was left to him (which we are retiring to sometime next year, I’m due to be made redundant no later than August 24 and we are selling up my flat and moving to north Norfolk), the bungalow was built in the 1970s and needs a lot of extra insulation and window upgrades, it has very old storage heaters one of which no longer works and still had it’s original old hot water cylinder that we plan to remove and replace, I hate radiators and my partner doesn’t want underfloor heating despite My best efforts to talk them round, so air to air is the compromise, seeing your system and the same make being used by several others has settle me on an air to air solution. And like you are planning to also a have a heat pump tank and are possibly looking at the Mixergy iHP. I will look forward to your next video on that! Throughly enjoy your videos. I’m planning a large solar panel and battery system too, my partner says I can use all my redundancy money on one and I’m currently planning on getting a system using emphases microinverters, solar panels and givenergy batteries, but (having listened to many Gary does solar vids and chatted to him about that I’m waiting until we are there as prices of solar installations are falling or will be by the time we move into our Norfolk bungalow. All our planned work is probably going to take long than I’d hope as I tend to overthink and so the planning stage will be extended as I rule out alternatives but so far all my above plans have remained my thoughts for several months now, so I think they are very likely to not change unless some new tech or newly improved solar panels etc. appear before our move. Thanks for hours of informative vids! Rob
That sounds fab, what a great opportunity to upgrade an old property. All your plans seem very sensible to me and I'm glad my videos (and Gary's) have helped with your research. Best of luck and enjoy your retirement!
@@tlangdon12 thanks for the info, I’ll do some price investigation on what Daikin’s internal units are like price wise and what they look like and whether anyone locally will install them. I’ve found the desire to spend money on my major eco improvements to our home locally a lot harder than I thought, I’m only willing to compromise on what I want to a degree, I’ve already had to decide to go further a field than I hope on the solar/battery system because no one locally would do my choice of the panels/micro inverters and batteries. Even getting things like the fridge and freezer I wanted locally was a hassle so I’m not taking anything for granted as available locally. But it good to know what I got told about hot water isn’t true in ever case.
Thanks for putting this info together Tim! Very interested in the rest of your journey - we are about half way through a transition to A2A in our house (Panasonic Ducted Upstairs, probably sticking with Panasonic but wallmounted cassettes for downstairs). Still have a big Veissman 111 boiler for our hot water but been looking for a solution away from that :)
Ah nice, I wish I'd looked more into the ducted A2A option back when we got our system installed. We're pretty happy with what we've got, and may have still chosen this route, but I should have spent more time looking into it.
@@TimAndKatsGreenWalk Yeah I think you have the Toshiba ones? Heard they are meant to be great also! Ducted is super quiet which is nice but we have 1 temperature control for the whole of upstairs is the only downside - but tbh this hasn't been a problem for 2 years as all the rooms are balanced nicely with the ducting and air flow.
@@stockbullfrog yes, we have the Toshiba Haori units, which we do like a lot. Ducted upstairs would definitely have been good though. One day I'll get around to doing the "what I would have done differently" video, which I keep meaning to do.
The Daikin Multi+ is the only system I know of that does this: www.daikin.co.uk/en_gb/press-releases/enjoy-greater-comfort-and-save-energy-with-the-new-multi--all-in.html
The HP cylinders are great. It's on my plan once a few other big jobs are out of the way. A point of note (I think): The higher the input temperature, the more efficient. I've seem some installs of this device in airing cupboards where the air input is ducted FROM the loft space and the air extract is vented outdoors (for summer time; roof spaces get relatively HOT). And in winter, the air extract is diverted back into the loft space to keep it a bit warmer. Point is, there are many ways to make use of the waste heat :). Have fun with this project.
Yeah, lots of venting options. Although the exhaust air is always cold (since the heat has been extracted into the water) so venting into the loft in winter would cool it down rather than warm it up. Venting that exhaust cold air into the house during summer on the other hand is definitely worth considering. It makes the piping more complicated, with duct switches etc. it just depends how much the extra effort is worth it.
Couple of points Tim, firstly if you use the heat pump with a Mixergy cylinder, you have to heat the whole volume as it has a recirculating pump. And usually when you have solar thermal, it's an indirect system so you aren't circulating tap water directly through the panels. It is far more efficient to be circulating a fluid like glycol. A key advantage of a heat battery is that you don't need to run any sort of boost cycle to kill off bacteria as there is no stored hot water. The Daikin Multiplus is the A2A system I'm aware of that can heat water.
Yup, someone else mentioned the Mixergy thing with the heat pump, that's something I didn't know. I believe the iHP does work more like the way the regular cylinder does though, with it heating from the top. I was aware that it's not the water you use that runs through the solar thermal panels, I was just keeping it as brief as possible since that wasn't too critical to mention. Good point about the heat battery. And thanks for reminding me about the Daikin Mulitiplus, I keep forgetting the name of it.
Love your approach to all this - clear and methodical without any preaching or nastiness so well done! My question would be are you facing the law of diminishing returns (in this case savings) in the quest to be totally self sufficient? If you have the funds to do so that's fine and very helpful for those of us who are still considering what to do, However, how many people can afford the sort of set up you have? Installation costs and ongoing maintenance, repairs etc to what are often relatively uncommon devices whose longevity is not really known and for which replacement parts may be very expensive and/or difficult to source readily and install. I'd be interested to know your total spend thus far v the savings you've made, what the break even point currently is and how that might change given the cost of your chosen new hot water solution. If any major parts of your setup failed beyond economic repair how would the replacement costs of that compare to say a new gas boiler or a problem with a the heart of a normal domestic electricy supply? Yes of course energy prices can always increase but the extent to which that's possible now must be limited to an extent by the very fact that we're much closer to the point at which people would ve freezing in their homes and business failures spiralling so the government would have to step in again to subsidise energy prices to avoid huge social unrest or unacceptable damage to the economy. I think what you're doing is very important and you know far better than I how complicated all these things are - how so many options are becoming available whose longevity and reliability haven't yet been tested over time and aren't yet common enough to benefit from cost savings due to scale of production. It's a problem in the car market with perfectly usable cars being rendered uneconomic to repair simply due to the cost of hugely expensive, scarce parts and limited suppliers. That's hardly green. I have a 12 year old Worcester Bosch Green Star condensing boiler which has been totally reliable (touch wood :) ), reduced our gas consumption quite a bit and cost me virtually nothing to maintain. I can heat the hot water by immersion if I so wish at cheap rates. A brand new one would cost c. £3k and will likely see me through another decade or so with little additional cost. My annual energy costs are around £2k with electricity being about 60-70% of that so I'm yet to decide what 'green measures' are going to be cost effective, all the time knowing that as time goes on newer, better and even more reliable and even greener alternatives will appear. For these reasons I'm reluctant to jump in and am finding your channel extremely helpful in forming my own opinions on how to proceed and would welcome your response to my questions. Cheers and good luck with what you're doing.
I posted a pinned comment regarding cost effectiveness since a few people have been asking similar questions, so go check that out. I'll address it in more detail in the next video as replying in length with the same answer to each question is taking up quite some time!
Yes you could have gone to the air to water system to warm your house and hot water, but in the summer is where the individual heat pumps come into their own as chillers.
@@TimAndKatsGreenWalk Same for me just got them installed and we had a mini heatwave here in the Scottish Highlands so appreciated the cooling from the Haori’s
Intake air from the loft is the way to get best efficiency and Mixergy told me that you can fit the heat pump part of the system in a different location to the cylinder (obviously with a distance restriction) As my cylinder is on the middle floor of my 3 storey house I am still not sure how the pipes would need to run and the £3k plus instillation is also a problem.
Ooh, that's very interesting. Our garage is directly below the airing cupboard so I wonder if I could install the cylinder in the airing cupboard and the heat pump in the garage. Hmm, very interesting indeed, thanks for letting me know!
@@TimAndKatsGreenWalk The reason air intake from the loft is good is that heat rising from the home means that you are taking warm air into the DHW Heat pump, which makes that heat pump more efficient, but make the home colder, unless your boiler or heating heat pump work a bit harder. Overall the arrangement isn't generally more efficient, but can avoid the DHW heat pump freezing in the colder winter months.
@@tlangdon12 yeah, I was replying about the split heat pump and cylinder not the air intake from the loft. I agree it's better to have both vents going to the outside.
Tim..I have commented before and declare as a Mixergy fanboy😊. Firstly I would say 5kwh a day for a couple for hot water is a “generous” amount, unless you have daily baths. 2 x daily showers from my Mixergy is circa 2.6 kWh. (50 litres) Notwithstanding that, max efficiency from a HP cylinder will be a COP of 2.5. So in your case Mixergy vs Mixergy HP , the HP will save you 3kwh a day…30p in your case….but costs at least £1000 more and needs more servicing ! Also note, the Vaillant HPTank is an all in one unit….whereas the Mixergy HPTank is 2 piece, so in a worst case failure its not a complete loss [And yes the Fischer storage is just a re-badged Sunamp- at more money !] Keep on the journey👍
Doesn't seem that generous (For references we use around 3-4kWh of energy for a shower here, and 6kWh for a bath. I have seen estimates as high as 8.5kWh for a shower. So 2.6 for 2 showers seems very very low to me.
We have rain head showers so that tends to use more water than a regular head. But I shouldn't have to justify our hot water usage. I'm glad you're able to use so little. The iHP looks like a good option for us but I'll be comparing it against several other options in the next video so it'll be an interesting comparison.
@@chriss4949 apology accepted. I'm sure it wasn't meant in any way to be a criticism of our water usage. It's always a danger commenting on differences in lifestyle!
Interesting options when considering A2A heating and how to heat DHW - we currently get approx 200-250 days of ‘free’ HW from PV diversion (hardly any in the winter due to the addition of a battery lat year which takes priority) BTW your explanation of how flat plate and evacuated tubes work wasn’t quite accurate - the water itself doesn’t circulate through them but through a heat exchanger mechanism depending on which type (usually filled with anti-freeze). Also evacuated tubes only have a header tank at the top - the tubes themselves are hollow much like a vacuum flask and have another tube within containing the heat transfer fluid which evaporates and carries the heat to the top to then be transferred into the header tank. They still work pretty well in winter and were all the rage along with thermal stores - they seem to have fallen out of favour over PV it seems but as a supplemental heat source could well fit the bill…
@@TimAndKatsGreenWalk true to some extent, but the benefits are that once you have them installed, there is no additional (electrical) energy input needed (for the most part) unlike the alternatives where you still need a source of electricity - that in itself is the biggest plus point - admittedly on really dull (or snowy!) days the immersion may need to come into play but £ for £ they may actually be the best value solution if you have the roof space...
@@Umski I showed these various options as a starting point for folks to do their own more detailed research if they were interested in any particular solution. I couldn't really describe every detail of every system or else the video would have been excessively long! And there are bound to be many other systems I neglected entirely. Regarding the solar thermal not needing electricity, I did mention it was the sun that did the heating and not electricity, so I think I covered that point in the video, as well as mentioning supplementary heating might be required in the winter.
Using the immersion heater, the cylinder will fill up very quickly with limescale. Like a kettle. Having 60-65 deg water circulating in the cylinder heat exchange coil, minimises limescale deposition.
Depends on your water hardness and the temperature but yeah, something to consider. Titanium immersion elements help prevent build-up too. Hopefully we'll be replacing our cylinder with a heat pump one next year in any case
Yes, although you'd need vents to the outside (possibly via the loft) and you might want to add some sound proofing to the airing cupboard to help mitigate the sound of the heat pump (like a loud fridge). But totally doable.
@@serraios1989 my one is in my garage but it would have fitted in my cupboard upstairs where the old water tank used to live (do water tanks live 🤔) You definitely need access to provide the air intake and exhaust two 6 inch holes. I didnt place it in the cupboard due to my concern about it having some noise but to be honest with the right amount of sensible sound proofing you probably wouldn’t hear it that much and if you have the heating period outside your normal bedtime then you probably want hear it at all
Very useful summary. One or two responses have alluded to this but have you done the breakeven between the existing immersion using night-time tariff (at worst) vs the same on the heatpumps cylinder taking into account the capital cost of the latter. On a different topic would love to see in future your analysis of Octopus Go vs Intelligent Octopus. IO sounds better with longer off peak, lower ppkwh and double export (so more like flux...which incidentally my powerwall optimised very well...ie choosing when to export to grid from battery). Currently on Go....and whether the powerwall gets through to 00:30 is extremely sensitive to the solar generation.
If you've seen those other responses regarding return on investment etc. then you'll have also seen my replies to them saying I'm not expecting the heat pump cylinder to pay for itself, I'm not doing it for that reason. I'll explain more in the next video but basically I'm aiming to reduce energy use, not necessarily to save a load of money. Regarding Go vs Intelligent Go, there's not a lot of analysis to do really, Intelligent Go is clearly better in every way, you just have to have a compatible EV or charger to get onto it. Sadly I have neither just yet, but I'm hoping that'll change in due course. In the Spring I'll be doing a quick check to compare Go, Intelligent Go, Flux, and Intelligent Flux, to see if it's still worth switching at that point, so keep your eye out for that video.
Point taken re breakeven...that was my own reasoning when getting solar and battery installed. I also nearly followed on with a mixergy tank but at the time could not find an approved installer to even discuss it! On the Go vs Intelligent Go I agree that the financials are clear and what I should have asked is whether you feel that the "handing control" of your car charging to Octopus have no unintended consequences. Myenergy (they are still testing with Octopus) sent me a data sheet....it's quite complicated and may need current settings on charger changed. Many of your viewers will have gone through this already if they have compatible chargers and would appreciate their comments. @@TimAndKatsGreenWalk
@@KenH-63 yeah, good question about handing over control of the charging to Octopus. I think I'd have to give it a try for a bit to see how it worked in practice. If I didn't like how it worked I could always switch back to Go. But that six hour off peak window would allow us to get another battery and charge up more to support our heating, so that would be too good an opportunity to pass up. I need to run the numbers on that one to see if getting that extra battery would actually be worth it, but my hunch is that it's on the cusp, so if that's the case Intelligent Go would be essential to making that work. Put it this way, I'd certainly give it a try!
@@TimAndKatsGreenWalk I now have IO and it does give the option in the app to switch off smart charging and charge when you want. I understand you must charge using it at least once per month for Octopus to have grid flexibility. Have not heard yet what happens if someone stays on manual.
You can wire the second element up to your Eddi and configure a Top and Bottom of the tank. Eddi will heat top first when boosting / solar excess and bottom when doing overnight heating. Benefit is you only heat what you need. It’s one of several configuration options in the Eddi manual.
@@TimAndKatsGreenWalk less heat up time and heatloss when less water required by using top one. lag any warm pipework in the airing cupboard. got our cylinder heatloss down to 68W for a 174L megaflo eco
@@waynecartwright-js8tw the heat loss from our cylinder is about 45W, so I reckon we're doing ok (I lagged the heck out of all the pipes in the airing cupboard).
True, although we occasionally use more hot water than usual like this weekend when the in-laws came to visit. In cases like this something like the Mixergy system would be pretty handy.
You should wire up the top and use that one instead and do something similar to the mixergy. There is a technology connections video explaining it. Also, I got a T Smart immersion heater that gives you some smarts for around 100 GBP.
Yeah, that's an option but we do sometimes need a bit more hot water than usual (when we have visitors, for example). Hopefully we'll get our replacement system next year in any case.
Does your current immersion have an adjustable thermostat? If not, you will be able to retrofit a thermostat with a relay for your immersion and you'll save many kWhs by heating the tank to 50 degrees instead of 60 degrees. Also a very cheap and simple upgrade compared to your other options.
I did tinker with the thermostat inside the immersion until it was at a temperature we were happy with, yes. It's not exactly user friendly and required a bit of trial and error but it's set where we want it now.
@@TimAndKatsGreenWalk Good to know you've already ticked that box! I was set on A2A until coming across your videos and considering the effects of the hot water long term. After a lot of planning, we've finally had A2W Vaillant Arotherm Plus installed and so far, so good. We are spoiled for choice these days.
@@UpsideDownFork good stuff. Yeah, the lack of hot water with A2A is pretty annoying, and the main downside, but hopefully we'll end up with a decent alternative.
Using a heat pump to charge a Phase Change store doesn't sound that efficient as the heat pump flow temp is above the melting point of the medium , which is above the required water temperature. Heating a water cylinder with a heat pump , the heat pump flow temperature is low while the water is cold & only rises as as the water temp rises so a better average COP is obtained ( in theory) .
The phase change system requires the same temperature water to heat it up as a hot water cylinder, so would work just fine with a heat pump running at 60 ish deg. So the COP would be fine. Even at 60 deg you'd still get a COP well above 2.
We went down the route of the sunamp due to not really having a great space for a cylinder. Its been great. 0 maintainence is certainly a win. Ours is only charged by either PV or more usually cheap rate. But its heatloss is so low I don't think about it. Paring it with a heat pump would make it cheaper to run, the upfront cost of the HP would probably not be worth it unless you were doing A2W
@@TimAndKatsGreenWalk Yeah, an integrated pump version would have been amazing. Though IHPs in cylinders feels weird to me as they are drawing the heat from the house to heat the water, which feels weird because airing cupboards traditionally used the heat lose of cylinders to dry clothes or keep towels warm,
So the only one I know of is the Daikin Multiplus system, but it turns out the hot water cylinder is quite small at 120 litres, so not great for larger households. And there is some debate about whether or not you can actually get hold of it in the UK just yet. It might be that we did end up making a sensible choice after all and wouldn't have chosen differently even if I had known about the Multiplus system last year, but there you go. Anyway, worth looking into in case it turns out to be suitable.
@@TimAndKatsGreenWalk Thanks. Definitely worth looking into I think you also made a fair point at the end ie: the heat pump cylinder making noise which could be annoying when the boiler atm is in my room, in a little cupboard which also acts as a walk in wardrobe. I do like the idea of keeping the walk in wardrobe, and having a heat pump cylinder outside. I'm not too keen on sunamp largely because of the reviews I've seen against them and them being fairly vague on their website BTW have you looked at a Zypho or similar? The idea is that they have waste water heat recovery which further helps save your DHW usage
@@waqasahmed939 you'd probably want the heat pump cylinder in a garage or similar, rather than outside. I'm not sure how weather resistant they are (electronics and such) and they would lose more heat when outside too. I have looked into the Zypho, looks interesting, but not something I'd install unless I was remodeling the bathrooms. One to keep in mind for such an eventuality though.
@@TimAndKatsGreenWalk That's fair. I do only have a small (uninsulated) garage too. I'm with you RE: only getting a zypho if remodelling. Otherwise they seem expensive as a one off I did however switch from an electric shower to a smart digital shower. I've got an en suite that already had a mixer too, and interestingly I found zero pressure drop when replacing the electric shower for a smart digital shower. I think the digital thingy regulates the pressure somewhat which is very useful when I don't have a cylinder . My initial rationale was : It's unlikely that I'll use the en suite at the same time as someone in the main bathroom. The guy before me was an auto electrician who wired the shower and lights together on the same circuit and that kept tripping my fuse. I was told that the wire was just within tolerance for the shower but not also for the lights too, and I figured I seriously reduce the risk of my house burning down due to a wire getting too hot and I reduce running costs if I move to a mixer I bought the smart digital one because it was £200 more and I thought that's not bad in the grand scheme of things I've now had a shower whilst the other main shower was on, albeit rarely, and I still found zero issues. That's a nice additional benefit I found out about the zypho later on however so if I remodel, I'll pop that in
@@waqasahmed939 goodness me. Yes, I can see why you'd want to change it. It's always tough to decide what's best to do. Good luck with whatever you decide! Although at least the digital shower seems to be working better for you.
I am just about to start a major renovation on a 1950's bungalow. I am starting off with a wrap around extension and a dormer in the roof. The front of the house will have external insulation fitted and as it semi-detached I am also going to include some insulation on the adjoining walls. The roof is East West just like yours so I will have 6 in-roof panels on the front and 6 panels on the flat roof of the dormer at the back. I have designed in a plant room, as the garage is being demolished, and that will have a Mixergy tank, a tesla battery, connections to the underfloor heating from the ASHP and an MVHR controller along with one or more new consumer boards and a power supply for the car charger. My question is this, can the ASHP support the Mixergy tank as well as the under floor heating? or should I try and power the Mixergy tank from the solar. I think I understand most of how everything works individually but it is how I combine the various elements that I get a bit lost (also planning on having the Harvi & Eddi). Your thought would be very welcome p.s. I love the channel.
Sounds like a great project, but there's one adjustment I'd suggest. You shouldn't need the Mixergy tank at all as most A2W ASHP systems will come with their own hot water tank, which will run from the heat pump too. So in other words you'll get both heating and hot water from the one system. If you're heating your water using the heat pump (which is what I would recommend) then you shouldn't need the eddi for solar diversion either, as it's much more efficient to heat the water using a heat pump (at 300% efficiency) than using direct electrical heating via the immersion and eddi (only 100% efficient). You could then export that excess solar instead using a good export tariff such as Octopus Flux in the Summer (and then switch to something like Go or intelligent Go in the Winter when the excess solar dries up). Whenever you're heating anything (home or water) then a heat pump is always the best option. I hope that makes sense.
Thank you so much for the heads up, I hadn't realised the ASHP came with it's own hot water tank, I was thinking of the Mixergy as It will only be me in the house most of the time and I liked the idea of only heating as much as I needed, presumably the standard tank will be fully heated. My reason for doing this is to have minimal cost in my old age and I only have the money now and when it's gone it's gone. Having read some of the other comments not having the Mixergy would also save on the servicing. Have I missed any tricks anywhere else?
@@christinewhite3749 so you'd probably find that a heat pump heating a full cylinder will still be significantly more efficient that a Mixergy tank heated only halfway. Although, you could probably get a relatively small cylinder to go with the ASHP system (120 litres, say), in which case you'd get both benefits. As for other considerations, the only other thing I'd suggest is taking a look at the GivEnergy All in One battery, which has similar specs to the Tesla Powerwall but is a lot cheaper.
a suggestion? you mention Tesla battery if you follow Tim's great suggestion of a GivEnergy battery, maybe consider TWO batteries? (say, 20KWh-24KWh). Might *still* be cheaper than Tesla PowerWall! my suggestion is based on the substantial eventual size of your home, to maximize self-consumption in summer and maximise off-peak charging in winter. it depends on your home and EV's consumption, and generation, across all seasons. installation costs are a *SUBSTANTIAL* proportion of the final cost; installing two at the same time is likely to be considerably cheaper than two installed separately. perhaps look to the associated GivEnergy EV charger for benefits from them being able to 'talk' to each other so they are both smarter
Thanks for adding to the conversation - I did look at other batteries but unless I am mistaken the Tesla seems to be the only one which can power the house in a power cut, others just let you have a couple of sockets so you can boil a kettle, we just don't know what the future holds and I would just like this little extra security, If I am mistaken please set me know.
Trying to decide between mixergy and sunamp at the moment… Mostly because of the boiler upgrade scheme requirement that the same heat pump has to do hot water as well…
I think the government will upgrade their schemes to take on board standalone ASHP water cylinders and A2A setups in the coming year as they adapt to the various options out there for people.
agree with being more efficient, but less is not always more…we went down the Fischer Aquafficient (210l) heat battery for simple reasons really: 1) size: no cylinder, moving parts whatsoever essentially space saving and a third of your cylinder size 2) zero noise & no annual servicing 3) compatible with solar & off peak charging….we literally never use the 210l available that is fully available and it recharges overnight (cca 5kW)….considering its off peak charging its a no-brainer to go down this route compared to 40-50db continuous noise and tripple the size solution just to get extra 3kW?with no real financial impact…
3 kWh per day quickly adds up. I'm glad you're happy with your Fischer system but that doesn't mean it'd be the best option for everyone. The point of this video was to show a sample of the available options so folks can make their own decisions based on what's important to them.
The 5kWh to heat up was my main concern with the Sunamp type setups. It’s the same direct electric heating of my old standard water tank. So any saving on usage is a good return. What was the cost of your unit to replace our hot water as the Sunamps where quite expensive. Agreed they are not as big in size but they do more or least take the same footprint so you gain more shelving space but thats about it. Agreed you can charge at cheap rates with a solar setup in the mix it helps during the summer will still take less to heat up the tank and I can schedule it to run at cheap rate times as well but it takes longer to heat so without solar I would use some non cheap rate tariff. With battery I can use that to offset the various rates and timings by power it from the battery when its be charged up by cheap rate electric
@@bobbazley5376 battery itself for the 210l v9 is 10.5kW capacity, but we never managed to fully deplet it…usual off peak charge midnight onwards with 4.5p. And yes if you have battery can be used but I dont see any reason as you already charge off peak or PV so daily grid is not needed. hot water is instant and box itself is never warm or hot.
@@TimAndKatsGreenWalk 3kW adds up, it does, so will your annual servicing cost so this argument is irrelevant…p.s. you should not take things personally 🙂 if you want a chunky noisy box-of course, the choice is yours
@@robert_minarik I did say I was going to install it in the garage out of earshot. My priorities are different to yours, simple as that, there's no need to suggest that my choice is inferior to yours somehow (I'm certainly not suggesting your choice was wrong, it's clearly something you're happy with and I'm glad for you).
Are you considering a thermodynamic panel? Instead of the outside unit you have a panel on your roof or wall. I haven't seen much on TH-cam about them lately though.
You mean like the solar thermal option I mentioned, or are you referring to something different? I think I'm pretty set on the heat pump cylinder at this point but if there's something I've missed I'd be interested to know.
Interesting.. Just for clarity and assuming a new water based ASHP where being fitted the ASHW-cylinder would not be needed? Would there be a differential between SCOP of an external heat pump plumbed to a specific compatible cylinder and that of a ASHW-cylinder? For some reason I had it in mind that the external ASHP only heated a hot water tank at a SCOP of 1 🤔
The SCOPs should be similar regardless of where the heat pump is installed (as long as the air is vented to and from the outside) . So an external heat pump would still heat a cylinder at a SCOP of 2.5+, maybe higher in some cases. The main advantage of the A2W system is that you then only need the single external heat pump, which would provide both space heating and water heating. Having opted for A2A instead I'd need that second heat pump for the hot water, unfortunately. In either case you need a cylinder to store your hot water, heat pumps can't provide hot water on demand.
For the ASHP cylinder would you not want to draw in air from inside? This would be more efficient as the air is warmer. The vent will want to go outside as the air will be cold, although in summer it would be good to be able to direct thisninside as well for cooling
So you can vent in a number of different ways and certainly in the summer being able to vent the exhaust cold air into your house can be beneficial and certainly doable with the appropriate pipework and switches. But you don't really want to draw warm air from your house in winter as you then have to replace that warm air with your heating system, so you don't really gain anything overall, if that makes sense.
Additionally, if you take air from inside the house envelope and exhaust it outside then you create a lower pressure inside the home. This will create draughts anywhere where the envelope doesn't seal perfectly to the outside. They may well be just where you don't want them! For example, the vented area under your ground floor (if you have such a thing) might become your air feed into the house. I am not sure I would want this musty, stale air as my house intake.@@TimAndKatsGreenWalk
Hi Tim thanks for another great vlog. I to didn’t know you could heat your hot water with an A2A system so I am looking at a Mixergy tank. I am told the heat pump on top of the tank is quiet?? So would be suitable for an airing cupboard?? The problem with all this change we are doing I have found little advice/ information on which direction to go. So have relied mainly on TH-camrs like yourself to make my decisions and I thank you for that and sharing your journey. Best regards Simon
Well, the heat pump on top of the Mixergy cylinder is not exactly silent, I think you would notice it. It'd be like having a particularly loud fridge in the airing cupboard, so you might want to consider some sound proofing treatment to be sure. Unless you can install it in a garage, say. Although another viewer did mention that apparently you can install the cylinder and heat pump in two different places, connected with the relevant pipes, so you might be able to install the cylinder in the airing cupboard and the heat pump somewhere out of earshot. I've not verified this just yet, but I'll be getting in touch with Mixergy to confirm. In either case you would need venting pipes to the outside for the heat pump, so that's something to bear in mind too.
@@simonperkins345 good question, that's not something I know the answer to for sure. You'd have to contact your ASHP manufacturer to see if you can do that.
Tim, your thoughts on this being a bit of a diminishing return? 5 units at 9p x 365 days approx. £165 p.a. for hot water reduce that to 2kw a day and your cost p.a. approx £65 A saving of £100 a year - less if you manage to end up on intelligent So isn't a further option Hot Water option simply to do nothing for the time being, perhaps even find a way to export just a little more and perhaps easily cover that £100 by other means?? Moving to Intelligent alone would cover that saving. I know, cars and chargers are the Intelligent issue. Just a thought?? All the very best Mike
It's a valid observation, for sure. However my main priority isn't cost saving (although clearly that would be nice too) it's energy saving. I realise I'm probably in a minority but as long as it's not unreasonably expensive to do so my aim is to reduce my energy consumption and increase my energy generation to the point where I'm a net exporter. I'm not really expecting to get a "return on investment" with this, I'm simply trying to find a way to reduce the amount of energy we use to heat our hot water. I'm sure a lot of people would consider that a silly thing to do but that doesn't concern me. We don't have kids, I have a decent job, we have the cash to spare, and this is what I consider a reasonable way to spend it. If I can help provide some information for a few folks who might be considering doing something similar then so much the better. Hopefully that makes sense.
@@TimAndKatsGreenWalk Thanks for taking the time and effort to make all the videos and replying in this case. It wasn't a hater or detractor comment at all and if I didn't ask it then someone would have and probably less sympathetically 😉. I know you don't surplus divert with Eddie as it doesn't suit your plan, but I can't get over how we just have all the hot water we need free from the sun courtesy of Edward! I started recording my peak boost sessions to see how efficient Eddied hot water had been, but soon stopped as it's probably only 10 - 20 times in 18 months. I'll be very interested to see your research on the Heat Pump tank you've chosen. Did start to muse over something similar after watching this. Our hot water tank looks uncannily like yours and thought I could draw air from the loft space 1m above, but quickly realised all that would do is to make the loft colder and probably increase thermal loss through the ceilings. Perhaps there is a soffit (the under side of the roof between wall and gutter) vent available?? Draw air from the south side of the house and vent to the north??? Anyway our timeline is first to treble or more our solar generation to something in excess of 10kw. Keep up the good work, looking forward to the next video. All the Best. Mike
@@oldgitflying yes, you're right about the loft space, it would decrease the temperature and therefore the heat drain from the house, so ideally you would vent to the outside. But if your loft is well ventilated anyway it might not be a big problem to just put both inlet and exhaust into the loft, or else vent through a roof vent, as you say. I expect there are some neat solutions for this. I don't mind at all you asking the question about investment return, it's a very valid question. I guess the main reason for this video is to show what options are available should someone need to replace their hot water system through age or failure, in which case you may as well get an efficient system as a replacement and the "return" part of that is less important since you'd be replacing it anyway.
Thanks for the video, very informative! I’m in the process of looking at air-to-air systems, can you tell me which ones do water as well? I haven’t been able to find any so far.
I think Daikin do an all in one system? Don't quote me on that though. They're certainly very rare in the UK, much more common on the continent. Perhaps that will change over time as more folks look to get systems like this.
Nice insight to the options available . Seems like a very small return for an expensive investment, have you done any calculations on return of investment if using off peak tarriff in winter and free to heat with solar in summer
Yeah, it's not the best "investment" for sure, but that's not really my aim here, I'm mainly trying to reduce our energy usage. If you have a good export tariff in the summer (Octopus Flux, say) then the opportunity cost for export is pretty high (20 p/kWh ish) so saving those kWh to export rather than heating your water is actually pretty beneficial. Even so, I doubt you'd pay for the kit in a reasonable time. Still, I present these options for those who might be interested. And if you have to replace your hot water system anyway (due to age, or failure) then it makes sense to do so with an efficient replacement.
I think mixenergy have control over the cylinder so they can dump heat into it when required at certain times and they charge to have someone come out to service every year also
Hi Tim, We currently have a 5.8KW solar system with a 5.8KWh battery. We're currently on Octopus Intelligent Go and are very happy with the tariff. I have set it up so it draws from the grid at night during low cost so that the solar feeds in during the day. We have seen the offerings of Air Source Heat Pumps with the government subsidy, meaning that te quotation we received from Octopus to fit an entire central heating (existing radiators) and hot water was just over £1000. Our house is relatively new build and has cavity wall insulation and good loft insulation. I was wondering what your thoughts on a ASHP in a four bedroom property would be. Would it actually save money? Given that it would be greener, for sure, than our current Gas system, the only concern I haev is that it would cost more to run than gas during the winter. I don't necessarily want to take the plunge if it's going to be costly to run. Our gas combi boiler is nearly ten years old, so it may be that that will have a failure at some point.....! Any thoughts, please? Thanks!
If you were on a standard tariff with no solar or battery system then running a heat pump would work out similar in cost to a gas boiler. With solar and battery to support it, when combined with IOG, you should find it a fair bit cheaper to run a heat pump than a gas boiler. You might find adding a bit more battery capacity helps too, as that extra battery can be used to effectively run more of your heating at the off-peak rate. We have 14 kWh of battery and last Winter we ran our heating almost entirely using off-peak power, all except the coldest days. However, even with a modest battery you should find that you can cover a good fraction of your heating in the autumn and spring with off-peak power or solar. I hope that helps.
@TimAndKatsGreenWalk thanks so much. At the price they've quoted, it seems to make perfect sense. We can't really afford another battery as well as a heat pump, but my head is fairly convinced about the potential savings. There aren't many real-world experiences out there at the moment, so you giving an answer is very helpful. Thank you!
@@Simonstunell1974 no problem. It's worth seeing how you get on in the first winter with the heat pump. You might find the amount of battery you have is sufficient. In either case you'll have some data to work with then.
What about the ZEB, it does central heating and water, very little change is needed if any, remove the boiler and plug in the ZEB. It would be great to get your thoughts on the ZEB.
The ZEB doesn't currently do hot water, but they're working on it. As and when they bring out that 'combi' version I might add it to the list, but for now it's central heating only. I wouldn't personally consider it for our situation as it's not as efficient as a heat pump based system, so wouldn't help us reduce our energy use, which is my main aim. It's definitely a good solution for some homes though, no denying that.
A ZEB is just an electric heat store. IIRC it's just a lump of concrete that you heat with electricity when it's cheap, and then extract that heat later in the day. That makes some sense for heating your house (if it's a lot cheaper than a heat pump), but a hot water tank is already a heat store for an immersion heater.
Quick question - so a 0.850kW electrical heat pump would generate 2.89kW of heat with a CoP of 3.4 (iHP Mixergy figures). The one you installed in your home provides enough heat?
I live in the US with an old gas powered hot water boiler and cast iron radiators that require very hot water to heat the house. Thinking about the possibility of either replacing the boiler with a Sunamp (if possible) or using Sunamp to heat a large tank of water and somehow use a heat exchanger in the tank to heat the water - instead of the boiler. How hot can the Sunamp heat the water? Any suggestions? I also am thinking of getting PV panels. Thanks, and great video!
The idea behind the Sunamp is to be a replacement for your hot water tank, rather than using it to heat a hot water tank. It's the Sunamp that then provides hot water to your home by passing cold water though it so that the heat is transferred to the water. The water comes out at 60 deg C from the Sunamp. The Sunamp won't provide water to your radiators though, it's only designed to provide hot water out of your taps etc. To fully replace your boiler you'd need a central heating replacement such as a heat pump (air to water or air to air, for example). Heating a home takes significantly more energy than heating hot water, so a Sunamp wouldn't cut it even if you did manage to hook it up to the radiators.
@@TimAndKatsGreenWalk Thanks Tim! but if I did replace my boiler with an air to water heat pump, could the water temperature be higher than 60 deg C, which would be needed in the cast iron radiators to heat my home?
@@marksTips466 you might be better off replacing your radiators at that point too. Most A2W HP systems work best running closer to 50 deg C, or below if possible.
I was going to suggest that a factor to consider is that the ASHP can run efficiently continuously - so your cast iron radiators would be "always on". In that scenario, could you keep the cast iron radiators? Simpler and lower cost. But on reflection a heating engineer can perform heat loss calculations and tell you the size of radiators needed - whether they go on/off or run continuously. In the UK, often even modern steel radiators might need to be enlarged when switching from boiler to ASHP. So the cast iron radiators may need to be replaced. in your post you don't say where in the US. if cast iron radiators*DO* need replacing, and you also need A/C in summer, then perhaps A2A cooling and heating might be a smarter choice?
I will try to get over my disappointment that you weren't doing cross stitch on a unicycle .....let it go me ! 🙈 I'm still not sure where A2A and grants are even though someone did say that combined with a HP water tank you could/might qualify. 🤔 So in the meantime I did sign up to trial with heata . (Hopefully I'll be selected) This is the data processing centre attached to the tank. Saw this fullly charged live. Might be worth your while 🤷♂️
Yeah, I saw a video on that data centre thing. Not something I'm considering but an interesting option, for sure. So it seems that A2A *doesn't* qualify for the BUS even if it comes with hot water too, which is a shame. A bit of an oversight in my opinion but there you go. Perhaps that situation will change but I wouldn't bet on it.
We have just had a hybird A2A/A2W system fitted in our bungalow that did qaulify for the BUS grant! Daikin Heatpump that runs to a unit that spilts it to a hot water tank and then water to 4 fan units in the loft that can run hot or cold air ducked into every room. Was a huge amount disruption but we had a dead gas combi and rusted out radiators. We have lost a fair bit of loft space but no radiators frees up a lot of wall space inside the property. We are a 3 bed bungalow and it cost us £8 after the old £5 BUS grant @@TimAndKatsGreenWalk
I'm currently weighing up options for replacing a gas combi boiler doing water and space heating (and maybe gain aircon in the process if I go down the A2A route). Thanks for this video, a helpful addition to my research.😀 Regarding the high-power (and relatively expensive) electric combi boilers, are they not sized as full replacements, to cover both hot water and radiators? I was under the impression that much smaller and cheaper units could be used just to heat the water (possibly separately for kitchen and bathroom), if space heating was being taken care of separately. Any thoughts on this?
Yes, you can get smaller units for hot water only but they still require very high power to create that hot water quick enough, and that will result in peak rate power draw so will end up more expensive to run than storing your hot water in a cylinder heated with cheap rate power (assuming you have the space for it).
@@TimAndKatsGreenWalk I see what you mean. I'm in a 1-bed flat so space is at a premium; I had given some thought to Sunamp, but was thinking that electric batteries (rather than heat batteries) would offer more flexibility. But I guess not if they aren't capable of supplying power at the required rate. My options for replacing the combi boiler are likely to be constrained; I'm on the 3rd floor with no balcony, but I do have a loft. I'm guessing I won't be able to get an external unit installed anywhere. I have seen that there are entirely internal A2A units available, for which you basically drill two holes in the wall in order to draw outside air through the unit. I've also been considering far infrared panels for heating (forgoing the aircon). I confess I've not entirely ruled out just getting another gas boiler.😕
@@colinmcconnell827 yes, that is tricky, I understand your predicament. A battery like the GivEnergy All in One can output at 6 kW, so that would be almost able to cope with an electric boiler running at 7 kW, say (which is similar to an electric shower power rating). But then you're spending £6k+ for that, and it takes up room, so something to factor in. It does sound like a Sunamp type system might be a decent option in your case for hot water. Regarding heating I'd certainly be interested to learn of any A2A systems that are entirely internal. Of course you then have the issue of the heat pump itself being inside and therefore being more audible (like with the heat pump cylinders I mentioned). In a flat that might make it quite intrusive. If the whole building could come together to implement a building wide system that would be ideal, but as always much trickier to organise!
@@TimAndKatsGreenWalk Sorry, I posted a reply yesterday which disappeared into the void; I think TH-cam may have thought it detected external links and not allowed it as a result. I'll try again, totally link-free - The internal A2A units seem to be mostly marketed with the terms 'condenserless' or 'twin duct'. You can find TH-cam videos demoing them, as well as websites from manufacturers and sellers. Some brand names are 'Powrmatic' and 'electriQ iQool'. Looking at them again, I notice that they are marketed as air conditioners with a heating mode. This may be connected with comments I've seen that they don't work well (or maybe at all) when the outside temperature gets below 5C. So, as well as the noise, that might be another reason to avoid them. As I said, I have a loft space. Most sources I have seen have said that it is not viable to install a condenser in a (suitably ventilated) loft, but I have seen one or two articles suggesting it can be an option. If could make that work, then I could potentially end up with an ideal solution where all the bulky, noisy stuff is hidden away and I just have a few vents in the ceiling. Have you come across anything like this?
@@TimAndKatsGreenWalk You can get entirely internal heat pumps - they wall mount with air intake/exhaust at the back which is then drilled through the wall. Externally all that is visible are some circular covers. My inlaws have two for heating/cooling their house, they seem to work well (scop of 3) but might be too noisy if you are in a comparatively small space.
I'd stick with what you have, just make sure the controls are always pulling energy when its cheapest/free. It's a shame the multi-split A/C guys don't provide a solution for water heating, you could imagine a fairly simple heat exchanger on one of the loops, with the right set of valves in summer it could dump heat from space cooling into the cylinder. I'm sure its coming and it might make me look at a refrigerant based system over a water based one when it comes.
There are some A2A systems that do effectively what you suggest, but not many, sadly. Daikin Multiplus is one such system. I didn't know about that when I first looked into A2A last year.
@@TimAndKatsGreenWalk Also the Samsung TDM+. The Daiken Multiplus has a 90/120l tank, which seems well below the MSC standard for tank size. The intent seems to be more flats than houses. So the TDM+ tank is too big for a UK domestic hot water cupboard, the Daiken multiplus probably won't allow two showers in a row, and would require daytime electric or battery cover to reheat if there is a brake between the showers and you don't need heating/cooling while it's doing that. I know the focus is on tanks, but I think you're beating yourself up for not going for an A2A+DHW option that doesn't really exist!
@@stevescott9289 perhaps you're right! I hadn't realised the Daikin tank was so small, that definitely wouldn't have covered our needs. Might suit some folks though, as you say.
@@TimAndKatsGreenWalk Only thing I'm trying to work out is if a A2A+DHW system could qualify the the Boiler Upgrade Scheme. Our house is 1980's warm air, which is unsuited to A2W (We have no radiators).
@@stevescott9289 this is a tricky question to answer and I've been unable to fully get to the bottom of it. On the BUS website it says (or said at one point when I last looked) that A2A didn't qualify even if it included hot water, but then another viewer said that they were able to get the BUS with such a system. Perhaps a canny (MCS registered) installer could make it happen but from my experience most "regular" AC installers know nothing about it, so it'd take some research to find a suitably qualified and knowledgeable installer.
Changing your current setup for hot water will never be cost effective. Better to spend money on more solar if possible. A quick change is to wire the top immersion heater instead of the lower one will mean you are heating less water.
Hello Tim, I am in the midst of taking quote to put mixenergy and then move onto putting heat pump, is this ok and more efficient than the cylinder that comes with heat pump?
I think I've worked out what you mean. You are getting a quote for a regular Mixergy cylinder but plan to get an air to water heat pump heating system installed later. Is that correct? If that's the case then I would suggest not getting a Mixergy cylinder as you will get a new cylinder with your air to water system which will work better and be cheaper than a regular Mixergy cylinder. There is certainly no need to get a heat pump cylinder (with the heat pump as part of the cylinder) if you are getting an A2W system. The efficiency is about the same for both.
You have done so much up until now that you are pushing a case of diminishing returns. If net exporter is your goal, have you not looked into custom built Evacuated Tube Collectors to mount on the house front in that Apex area with the cylinder in the loft behind them for hot water. Like I said, custom....so it looks good and becomes an external house feature. Years ago people thought solar panels were strange and today they are everywhere.
Oh, I totally appreciate that it's not necessarily worth it in terms of cost doing this extra stuff. But I'd like to do it anyway (gotta have a hobby, right?) and it gives me something to talk about on the channel! It's a bit of a rabbit hole, all this, and in some respects I do this stuff because I find it all really interesting and figured it was worth sharing some of the research I've been doing. Regarding the evacuated tube collectors, that would certainly be a lot more expensive to install than a heat pump cylinder but I might investigate that option at some point in the future, once I've run out of other stuff to do!
Very interesting indeed , listening to you just tells me how little I know in regards to all of this modern stuff for want of a better word on the market , I like the idea of getting rid of my gas and getting a heat pump , but never seem to be able to find any information about the cost between a heat pump and a gas boiler , hear lots about how efficient the heat pumps are , tend to hear figures such as oh the heat pump is 160% or 400% more efficient well Great but how much is the cost from October to March month by month with cost , it’s like as though the true cost is being hidden, not the cost of the heat pump but the cost of running it , all people say oh it depends on what tariff you’re on yes that’s seem to be a cop out as I see it , there has to be some kind of chart or ball park figure yet nowhere can one find this information. Yes you will need a whiskey to get through this message at least you will be warm in the inside.
The simplest way to do the calculation is to look at the SCOP (seasonal coefficient of performance) of the heat pump. A SCOP of 3 means it generates 3x as much heat as the electricity it uses. A gas boiler is about 80-90% efficient so effectively a SCOP of 0.8-0.9. Gas currently costs about a third as much as electricity (give or take), so a heat pump will cost about the same to run as a gas boiler. Then the tariff comes into it of course, but there's your ball-park figure. For us, we're able to run our heating using solar and battery (which has been charged up at cheap overnight rates) so it does then make it significantly cheaper than a gas boiler, and the water can be heated overnight too, using that cheap power. I hope that helps a bit.
@@TimAndKatsGreenWalk That’s probably the best answer I’ve ever seen , I think that whiskey has reached the logical nerve. I’ve watched a few of your videos which are very good by the way , I don’t have the money for solar or battery set up, just trying to get warm in the most efficient way and my biggest fear is not being able to afford to run the heat pump , irrespective of the efficiency of the heat pump compared to gas boiler I have this underlying concern it’s going to be three times more expensive with the bills. If someone could prove to me that here are the bills month by month from October to march comparison and there’s no difference, I would put my order in tomorrow, but my gut feeling is they can’t and it is three times more expensive to run, I’ve started to look at wood burners now which is crazy and even I think it’s crazy that I’m looking in that direction, maybe the way forward is for the electric companies to those who buy a heat pump don’t have 15% of their bill to pay for the green agenda that way the cost of running the heat pump would be more in line to those who have gas bills .
Running a heat pump is definitely not three times the cost of running a gas boiler. It'd be comparable, maybe a bit more, maybe a bit less, but certainly not three times more!
@@KavanOBrien there are various factors at play here you will use more electric than you normally use during the winter months as thats due to using an ASHP to do your heating (be that air2water or air2air) but to heat water within an ASHP is much more efficient than heating it with gas for the same energy input. The main issue is ASHP have a lower heat output so radiators may need to be upgraded and just doing insulation will improve the heating. The main point is that everyone’s house is different and their existing services are different and the need to upgrade or replace is different. I had oil I wanted to replace that with electric only solution as I have solar and Battery storage which absolutely reduces my monthly costs and offsets the high rate tariff periods. There is a payback period for my solar and battery but it will at current rates will be paid back full in 8 years total (ive had just under 3 years so 5 to go) but that is assuming prices stay as they are which I just dont see happening so when it utility prices go up then my return period will come down. I dont think a wood burner is viable as you still need to get a wood burner, then the wood and the time it takes to setup and clean. Unless you have free access to wood and the right type of wood not something that will burn in minutes.
@@bobbazley5376 heard every story known to man and beast, I live alone only have an old age pension coming in but would still like to do my bit for the green agenda, don’t have money for solar or battery storage or update radiators , it might help people in my position if the electric companies took off the 15% of the bill for the green agenda for those who are trying to do their bit ,
I am all in favour of A2A heating but why did you get rid of your gas boiler and then install such a massive tank? Doesn't make sense as heating water by electricity is far more expensive than having shower with a combi. What else do you wand hot water for anyway as I'm sure you have a dishwasher and washing machine both of which run on cold water. PS the top immersion is so you can heat a smaller amount of water which saves money
The tank was already there as part of the existing system, we didn't install it. It costs us less to heat via the immersion than the gas boiler because we do it using off peak power. I've got plenty more videos that cover all of this stuff, so go check those out.
I've seen a couple of options but realistically it's more disruption than I'm willing to undertake at this stage (would require ripping up the showers etc. for example). If we were to ever need to do work on the showers/bath then I'd look into getting something like that retrofitted at that stage, since it'd be easier to do while other work was going on.
@@TimAndKatsGreenWalk Yeah. They are a no-brainer in new constructions but pretty expensive otherwise. Although I think mentioning them in your videos will inform people of their existence
I wouldn't change what you have apart from wiring the top immersion you will never get your return on investment an immersion costs £20 changing your unvented cylinder for something else will cost thousands im a heating engineer of over 30 years and ive seen new hot water systems that are all singing and dancing and they don't last
Although what you say is valid, I'm not actually doing this for a return on my investment, my main aim is to reduce our energy usage, as long as it's not prohibitively expensive to do so (see previous video in this series linked in the top right corner). I'm sure a lot of people would find that strange but there it is.
Hello Tim, I have an Ecocent version of your favoured ASHP on tank. It’s excellent! Very efficient. It draws from the landing, unlike your plan and vents out from the attic. It’s not that loud. We only hear it when we walk past the airing cupboard where it is. I recommend, but, like @buddywheels, if I had to replace it, Sunamp really interests me. Only issue with Ecocent is that it needs a pump to capture condensation. It recently went wrong and dropped water into the downstairs shower room. It happened during Storm Ciaron, which freaked me out; how could rain come in sideways and not from the roof?! Other issue is that it’s not great at handling a houseful. We are normally three but when daughters and spouses come down from London, it runs out and takes time to recover. Yes, there is a boost but fast it is not. Alex
PS; like you we have a split system. But unlike you, central heating is a pellet boiler. In my defence, it came with the house. Apart from its lack of eco credentials, it’s effing hard work!! I dream of a system where I don’t have to feed it everyday and riddle ash!! 15kg of pellets a day!!! When my ship comes in it’s going!!!!
The way you describe it, it sounds like it sucks heat from the heated space of the building, and then vents this into the loft space (aka the uninsulated space)? Surely thats not right?
I also have an Ecocent 300. It works very well as it gets its air from the MVHR system which is warm and so improves efficiency. You would think this would cool the house but that does not seem to be the case. I agree it is slow to heat the 300 Lt of water when we have visitors but you can set it so it runs all the time to maintain a programmed temperature. When there is just 3 of us in the house I have it run in the night when we have cheap elec with a top up during the middle of the day. The main issue I have with the system is the terrible service from ESP. These type of integrated ashp/dhw tanks are very popular in the US. If you want one just steer clear of ESP
Yes, it doesn’t seem to cool the house. And it was explained to me that it was more efficient, as you describe. Thank you for the operational tips; v helpful!!
Regarding cost effectiveness or "return on investment" for these various systems, I'm presenting these as options for folks looking to replace their hot water systems for whatever reason, e.g. replacing a broken or old system, or simply because they want to, I'm not considering the cost implications here, it's up to you to do your own calculations to determine if you feel it's worth it or not. I'll explain my own reasons for doing this in the next video, so look out for that one in the coming few weeks.
Only just came across this channel, loving it already. My biggest draw is that your presentation is not "Stop doing that! do this!" Instead, you're very clear about "Here are some more options for you to consider"
Thank you, I really appreciate your kind words. I absolutely try to not be prescriptive about these things as I know full well that different people have different priorities so I'm glad that comes across. I hope you continue to enjoy the channel.
Many thanks, Tim. Jolly interesting. The heat pump cylinder is a revelation.
Indeed. After we got the A2A system I started wondering if such a thing existed and lo and behold they did! There were only two on the market that I could find back then but now I know of at least four, so I'll be covering them all in the next video, comparing the specs.
11:36 - was my way of thinking till yesterday, when Vaillant confirmed, that our aroSTOR's hot water storage cylinder can't be individually serviced, so now that it ruptured, we'll have to dispose of the whole unit - even though the HP is working completely OK (like well, now it's OK, as the compressor had to be changed when the unit passed 18 months service time.)
Dang, that's annoying. We went with the Mixergy iHP which is in two parts, cylinder and HP separate, so with any luck if something similar happens to ours it wouldn't all need replacing. Time will tell, of course, you never know if that would work in practice.
well,@@TimAndKatsGreenWalk, I would maybe use some stronger language, but it is what it is. so my idea now is to go with a Sunamp thermal battery (should be good for 40k cycles, not mentioning it has 10 years of warranty) and hook it up to an air-source heat pump (ASHP) and when we get one installed, a PV system. when and if the ASHP wouldn't be able to produce decent amount of forward going temperature (which can eventually happen here in Hungary) then we still have the grid to feed into the Sunamp. I can't yet think of a more minimalist setup, that involved lesser parts.
@@tamaskovats that sounds like a good plan. I hope it works out better for you than the aroSTOR!
Great summary Tim and really useful to see all of this condensed and explained in one video. I installed an ASHP in May which complements my PV system. Working really well and, though expensive, delighted to be free of fossil fuel!
Very nice. I'm glad you're happy with your system. The combo of PV and heat pump is ideal, really.
Great video Tim and all the options you mentioned are exactly the same process that I went through prior to my final choice about 3 months ago. The Mixergy by it self seemed a good option as it had some clever way of heating the water just enough for what you actual needed to use but the cost/efficiency ratio for me wasn’t enough to warrant the cost to buy it. They have indeed brought out a ASHP version that sits on the top of the cylinder but I dont think its available yet and from what i understand on pricing it wont be as competitive as other ASHP all in one cylinders.
The Sunamp was one that I looked at about 2 years ago and they do look to be efficient for what they do but I felt that they had some major points that put me off, first is the actual weight of them, they are incredible heavy due to the internal heating mixture and just getting it into a house might be an issue especially if you plan on having it upstairs in the traditional location for hot water tanks. They do use much less room but probably the same footprint as a water tank just not as high. I didnt like the fact that I couldn’t obtain clear efficiency rates for what it would cost to charge the full unit and how much hot water it would provide. The other company Fisher - basically use a Sunamp which is rebadged from what I read back when i was looking at them.
I decided on an ASHP all in one unit after much research and making sure i had a a hot water replacement for when I replaced my old oil boiler which did my heating and hot water. I went with the same setup for heating the house as you with the Toshiba Haori units and so far they are working out very well. Roll on the cold weather for the real test ! . The ASHP all in one unit I went for in the June of this year was chosen as it was more or less the only one I could easily obtain and at the price point that I was happy with. Installation was easy for my plumber, who had never installed an ASHP water tank previously but it was exactly the same type of water tank install as any other traditional water tank. He did worry about the ASHP part but he didnt have to do anything other than plump it into my existing hot water pipes and the electric. The Air flow is important so the location of these units needs to be able to get two 6 inch airflow pipes out to the outside of your house. The noise of them with the air flowing is minimal but I expect having it located in an upstairs hot water tank cupboard would not be the ideal place. I located my where my old oil based boiler was which was in the garage attached to my house and that gave me one of the air intake holes already due to the old flue for the oil boiler. So far I have seen at least a 50% decrease in my electrical use since installing it compared to heating my old hotwater tank on the electric element only. In summer I expect that rate to become very efficient but as we get colder days now i will reduce but if it saves even 1 kWh per day then its still a saving.
I’m looking forward to your next video and to see what you finally went for. (I’ve not mentioned what I’ve got as the setup until after you have made your video) thanks for doing the videos :)
Well, the next video will have a lot of specs comparisons so buckle up! It's good to hear you've had success with your choice and I'm looking forward to getting this sorted next year.
We switched to a heat pump water heater a few months ago and it works well in just heat-pump mode. We can use immersion elements if we somehow need them. If you have the right space and setup for it, it's great.
Cool, that's good to know. I think it should work well for us too.
Another great and informative video, thank you. I am looking into an Air to Air source heat pump but I might cheat and try and get it all sorted in one go, like the new Daikin all in one solution. Though currently I have a combi boiler so need to find space in a modern house which isn’t easy. Looking forward to your next video going into more detail.
Yeah, space for the cylinder is the killer. We're lucky we have room but I can see that being an issue for lots of folks who want to get heat pump heating systems that requires a cylinder for the hot water.
@@TimAndKatsGreenWalk This is the big problem for most smaller properties including flats and apartments. Heat pumps are more efficient, but you can't justify the cost of a powerful heat pump for a small property if you only need the maximum power to heat DHW quickly - low and slow is the heat pump mantra so finding somewhere to fit a water tank is necessary if you want to use a heat pump. I wish that rectangular tanks were more common as these maximise the volume of water stored. It would also be nice if Vaillant did a version of the aroSTOR that could use a remote cylinder, like the Oschner Europa Mini can. Oschner reliability seems to be lower than Vaillant though.
My Eddi uses around 7 to 9 kWh of electricity to heat the DHW cylinder. Havng an ASHP, I found it was 2 to 3 kWh to do the same . For now, the Eddi is triggering a home assistant automation to then turn on the ASHP to heat DHW, when there is sufficient spare solar.
You have found some interesting options for those with the air heating system as you have.
Very neat use of the eddi. Not sure what to do with mine once I get a heat pump for the hot water. Might give it away to someone who could make better use of it.
@@TimAndKatsGreenWalk You can use the Eddi to operate the heat pump for the hot water. The Eddi has some neat features to allow it to run the heat pump if there is enough solar pv generation to do so, and to use the immersion heater when there isn't. There is TH-cam video called "The ULTIMATE Solar Heat Pump HACK" on the Artisan Electrics channel that shows this being setup.
Very informative video. We made the conscious choice of cutting down our fossil fuel use and installed PV 3 yrs ago and is a 2 electric car household. I have been waiting to change our 12 yr old veissman when it gives up the ghost and was disappointed when Octopus came and did the survey for a Daikin HP and was told we would need to put the pump in the garden as the regulations didn't allow installation in the side ( due to lack of space, space is premium in manchester suburbia even with large houses). They also wanted us to have absolutely humongous radiators and suggested running the pump at 45C. To top it all the guy who came whispered in my ear to stick with the boiler. My boiler died 2 weeks ago and I am changing to a system boiler (98% efficient Worcester Bosch ) with a tempest single coil HW cylinder hoping to heat the water at night with my cheap IO tariff and surplus PV elec during summer. While i want to reduce my energy use I am also a pragmatist and do not want to spend huge amounts for Sunamp and mixergy like devices. I feel exporting with the new Octopus tariffs does both for me. My only disappointment is sticking with natural gas for heating.
That's fair. They really need to loosen the planning requirements if they're serious about getting people to install heat pumps. It's ridiculous at the moment and it's really holding things back.
@@TimAndKatsGreenWalk My cylinder is going to be 250L, I was under the impression it would need about 4 hrs to heat this up, but was a bit confused about your comment in an earlier video of yours about hot water times 20-30 min twice daily.( 3 tips on reducing gas usage). Are you talking about something else? Also what is your opinion about adding a solar boost to use PV on bright days? Will probably use more of my own energy though will lose money on it with the export tariff being very attractive.
@@sukugeorge67 yeah, that sounds about right. We did only need about 40 mins to heat our hot water when we had the gas boiler (we use between 100 and 150 litres per day), whereas now it takes more like 2 hrs with the immersion heater, because it's less powerful than the gas boiler. A heat pump is also less powerful than a gas boiler so will take longer too. You may find you use less than a full tank each day so will only need to heat back up what you used the day before, which will take less time.
Old immersion tanks used to have 2 heater elements because of economy 7 switched electric. One element was controlled by the grid daily, and the second was used as a boost function if you needed more hot water during peak hours.
Yup
Thanks Tim and Kat. I love the fact that i can pretty much find all the information i need on any thing to do with going carbon free on channels like yours excellent excellent excellent. I am at the beginning of my journey into this. My plan is, solar on east-west roof, givenergy all in 1, zeb boiler and mixergy water cylinder. We're on octopus go as we ha an ev, so would use cheap rate over night to charhe zeb when not enough solar, hopefully winter only. Not sold on heat pumps as we have a 1950s bungalow with a double dormer that has micro bore up there. Ps just bought the thermal camera from the link in your video.👍
Nice. Might also be worth keeping your eye on the new Octopus Cosy 6 heat pump that's coming soon, too. That's a "high temperature" HP so might suit you better than the existing ones, as you can drop it in and keep all your existing pipes and rads. And given the boiler upgrade scheme is now £7.5k you might find it's essentially free to install!
I looked into a sunamp before we had all of our system changed. It worked out VERY expensive with an A2W ASHP as it needs to be specced to be high temp. The PCM in the Sunamp needs 60C+ in order to charge.
I went with a Mixergy. It can really only be half filled by electric directly. When using the heat pump it needs to be all done. The good thing is it uses an external plate heat exchanger so transfers more of the heat energy to the tank water. Tbh, in hindsight I would have gone for a Mitsubishi cylinder along with our Ecodan and used the Mitsubishi smart controls.
Hindsight is a wonderful thing. We live, we learn, we realise we should have done things differently! Oh well. Sounds like you got a decent solution in the end though.
I live in spain, i put one of those tube systems on my roof terrace 3 years ago. they work great for spain. i found i needed to put one of those electric filaments in the place it stores the water for about 6 weeks in the winter. Now bear in mind that the sun is out here for most of that time about 16c. So not sure how they would work for most of the time in Great Britain.
Yeah, I can imagine it's ideal for Spain. It's definitely viable in the UK over the summer but I expect it'd need more than six weeks of top-up heating over the winter. I'd be interested to hear from anyone in the UK with such a system to share some real world experience.
I've also been looking. I liked the Vaillant aroSTOR a lot - simple local controls which do most of what you need. Option for a voltage free contact to run either heatpump or "backup" resistive heater, so easy to add to home automation and keep everything local.
Then mixergy put together their own heatpump integrated cylinder and started throwing mud at the serviceability and limited warranty of the "competition" (Heatpump dies -> new cylinder), but I don't want mixergy as they're asking for too much money for something overly dependent on their cloud service... which put me off both systems, and the gas combi I have now is working (if more carbon intensive than I'd like..)
The Daiken looks interesting, previously looked at the Samsung EHS TDM+, but the indoor water unit is huge and won't fit where the old water cylinder was...
There's also the Dimplex Edel. I'll be covering that and the others in the next video.
@@TimAndKatsGreenWalk While they look cosmetically very different, the control system looks very, very similar to the aroSTOR. Might be the same OEM for the Heatpump?
@@stevescott9289 I'm not sure. I plan on comparing all the specs and data sheets so if they are suspiciously similar then you might be right. I had a feeling they were a bit different though when I first looked.
Hi Tim, we are planning a rather similar air con and heating solution to you, and just to make you feel better about your choice I’ve been told (but I’m no expert) that all the air to air heat pumps available in the UK can’t do water as well, there are ones that do, available in the EU but they haven’t come to us here in the uk it seems.we are planning to upgrade my partners family bungalow, that was left to him (which we are retiring to sometime next year, I’m due to be made redundant no later than August 24 and we are selling up my flat and moving to north Norfolk), the bungalow was built in the 1970s and needs a lot of extra insulation and window upgrades, it has very old storage heaters one of which no longer works and still had it’s original old hot water cylinder that we plan to remove and replace, I hate radiators and my partner doesn’t want underfloor heating despite My best efforts to talk them round, so air to air is the compromise, seeing your system and the same make being used by several others has settle me on an air to air solution. And like you are planning to also a have a heat pump tank and are possibly looking at the Mixergy iHP. I will look forward to your next video on that! Throughly enjoy your videos. I’m planning a large solar panel and battery system too, my partner says I can use all my redundancy money on one and I’m currently planning on getting a system using emphases microinverters, solar panels and givenergy batteries, but (having listened to many Gary does solar vids and chatted to him about that I’m waiting until we are there as prices of solar installations are falling or will be by the time we move into our Norfolk bungalow. All our planned work is probably going to take long than I’d hope as I tend to overthink and so the planning stage will be extended as I rule out alternatives but so far all my above plans have remained my thoughts for several months now, so I think they are very likely to not change unless some new tech or newly improved solar panels etc. appear before our move. Thanks for hours of informative vids! Rob
That sounds fab, what a great opportunity to upgrade an old property. All your plans seem very sensible to me and I'm glad my videos (and Gary's) have helped with your research. Best of luck and enjoy your retirement!
Daikin's Multi+ air to air heat pump is available in the UK and will do DHW.
@@tlangdon12 thanks for the info, I’ll do some price investigation on what Daikin’s internal units are like price wise and what they look like and whether anyone locally will install them. I’ve found the desire to spend money on my major eco improvements to our home locally a lot harder than I thought, I’m only willing to compromise on what I want to a degree, I’ve already had to decide to go further a field than I hope on the solar/battery system because no one locally would do my choice of the panels/micro inverters and batteries. Even getting things like the fridge and freezer I wanted locally was a hassle so I’m not taking anything for granted as available locally. But it good to know what I got told about hot water isn’t true in ever case.
Thanks for putting this info together Tim! Very interested in the rest of your journey - we are about half way through a transition to A2A in our house (Panasonic Ducted Upstairs, probably sticking with Panasonic but wallmounted cassettes for downstairs). Still have a big Veissman 111 boiler for our hot water but been looking for a solution away from that :)
Ah nice, I wish I'd looked more into the ducted A2A option back when we got our system installed. We're pretty happy with what we've got, and may have still chosen this route, but I should have spent more time looking into it.
@@TimAndKatsGreenWalk Yeah I think you have the Toshiba ones? Heard they are meant to be great also! Ducted is super quiet which is nice but we have 1 temperature control for the whole of upstairs is the only downside - but tbh this hasn't been a problem for 2 years as all the rooms are balanced nicely with the ducting and air flow.
@@stockbullfrog yes, we have the Toshiba Haori units, which we do like a lot. Ducted upstairs would definitely have been good though. One day I'll get around to doing the "what I would have done differently" video, which I keep meaning to do.
Would love to hear more about a2a that can also do hot water.
I don't know much about it, I'm afraid.
The Daikin Multi+ is the only system I know of that does this: www.daikin.co.uk/en_gb/press-releases/enjoy-greater-comfort-and-save-energy-with-the-new-multi--all-in.html
I decided I should do a video on this: th-cam.com/video/9domQlKtbBQ/w-d-xo.htmlsi=O4bEhr43rXErIFoh
The HP cylinders are great. It's on my plan once a few other big jobs are out of the way. A point of note (I think): The higher the input temperature, the more efficient. I've seem some installs of this device in airing cupboards where the air input is ducted FROM the loft space and the air extract is vented outdoors (for summer time; roof spaces get relatively HOT). And in winter, the air extract is diverted back into the loft space to keep it a bit warmer. Point is, there are many ways to make use of the waste heat :). Have fun with this project.
Yeah, lots of venting options. Although the exhaust air is always cold (since the heat has been extracted into the water) so venting into the loft in winter would cool it down rather than warm it up. Venting that exhaust cold air into the house during summer on the other hand is definitely worth considering. It makes the piping more complicated, with duct switches etc. it just depends how much the extra effort is worth it.
Couple of points Tim, firstly if you use the heat pump with a Mixergy cylinder, you have to heat the whole volume as it has a recirculating pump. And usually when you have solar thermal, it's an indirect system so you aren't circulating tap water directly through the panels. It is far more efficient to be circulating a fluid like glycol. A key advantage of a heat battery is that you don't need to run any sort of boost cycle to kill off bacteria as there is no stored hot water. The Daikin Multiplus is the A2A system I'm aware of that can heat water.
Yup, someone else mentioned the Mixergy thing with the heat pump, that's something I didn't know. I believe the iHP does work more like the way the regular cylinder does though, with it heating from the top. I was aware that it's not the water you use that runs through the solar thermal panels, I was just keeping it as brief as possible since that wasn't too critical to mention. Good point about the heat battery. And thanks for reminding me about the Daikin Mulitiplus, I keep forgetting the name of it.
I forgot to mention a thing called the BOLT. It’s an electric boiler but with a built in battery.
@@sjcsystems ah, cool, I'll take a look.
Love your approach to all this - clear and methodical without any preaching or nastiness so well done!
My question would be are you facing the law of diminishing returns (in this case savings) in the quest to be totally self sufficient? If you have the funds to do so that's fine and very helpful for those of us who are still considering what to do, However, how many people can afford the sort of set up you have? Installation costs and ongoing maintenance, repairs etc to what are often relatively uncommon devices whose longevity is not really known and for which replacement parts may be very expensive and/or difficult to source readily and install. I'd be interested to know your total spend thus far v the savings you've made, what the break even point currently is and how that might change given the cost of your chosen new hot water solution. If any major parts of your setup failed beyond economic repair how would the replacement costs of that compare to say a new gas boiler or a problem with a the heart of a normal domestic electricy supply? Yes of course energy prices can always increase but the extent to which that's possible now must be limited to an extent by the very fact that we're much closer to the point at which people would ve freezing in their homes and business failures spiralling so the government would have to step in again to subsidise energy prices to avoid huge social unrest or unacceptable damage to the economy.
I think what you're doing is very important and you know far better than I how complicated all these things are - how so many options are becoming available whose longevity and reliability haven't yet been tested over time and aren't yet common enough to benefit from cost savings due to scale of production. It's a problem in the car market with perfectly usable cars being rendered uneconomic to repair simply due to the cost of hugely expensive, scarce parts and limited suppliers. That's hardly green.
I have a 12 year old Worcester Bosch Green Star condensing boiler which has been totally reliable (touch wood :) ), reduced our gas consumption quite a bit and cost me virtually nothing to maintain. I can heat the hot water by immersion if I so wish at cheap rates. A brand new one would cost c. £3k and will likely see me through another decade or so with little additional cost. My annual energy costs are around £2k with electricity being about 60-70% of that so I'm yet to decide what 'green measures' are going to be cost effective, all the time knowing that as time goes on newer, better and even more reliable and even greener alternatives will appear. For these reasons I'm reluctant to jump in and am finding your channel extremely helpful in forming my own opinions on how to proceed and would welcome your response to my questions. Cheers and good luck with what you're doing.
I posted a pinned comment regarding cost effectiveness since a few people have been asking similar questions, so go check that out. I'll address it in more detail in the next video as replying in length with the same answer to each question is taking up quite some time!
Yes you could have gone to the air to water system to warm your house and hot water, but in the summer is where the individual heat pumps come into their own as chillers.
Yes, indeed, that was one reason we went with A2A. We were very glad of that in early September, for sure!
@@TimAndKatsGreenWalk Same for me just got them installed and we had a mini heatwave here in the Scottish Highlands so appreciated the cooling from the Haori’s
Intake air from the loft is the way to get best efficiency and Mixergy told me that you can fit the heat pump part of the system in a different location to the cylinder (obviously with a distance restriction) As my cylinder is on the middle floor of my 3 storey house I am still not sure how the pipes would need to run and the £3k plus instillation is also a problem.
Ooh, that's very interesting. Our garage is directly below the airing cupboard so I wonder if I could install the cylinder in the airing cupboard and the heat pump in the garage. Hmm, very interesting indeed, thanks for letting me know!
@@TimAndKatsGreenWalk The reason air intake from the loft is good is that heat rising from the home means that you are taking warm air into the DHW Heat pump, which makes that heat pump more efficient, but make the home colder, unless your boiler or heating heat pump work a bit harder. Overall the arrangement isn't generally more efficient, but can avoid the DHW heat pump freezing in the colder winter months.
@@tlangdon12 yeah, I was replying about the split heat pump and cylinder not the air intake from the loft. I agree it's better to have both vents going to the outside.
Tim..I have commented before and declare as a Mixergy fanboy😊. Firstly I would say 5kwh a day for a couple for hot water is a “generous” amount, unless you have daily baths. 2 x daily showers from my Mixergy is circa 2.6 kWh. (50 litres)
Notwithstanding that, max efficiency from a HP cylinder will be a COP of 2.5. So in your case Mixergy vs Mixergy HP , the HP will save you 3kwh a day…30p in your case….but costs at least £1000 more and needs more servicing !
Also note, the Vaillant HPTank is an all in one unit….whereas the Mixergy HPTank is 2 piece, so in a worst case failure its not a complete loss
[And yes the Fischer storage is just a re-badged Sunamp- at more money !]
Keep on the journey👍
Doesn't seem that generous (For references we use around 3-4kWh of energy for a shower here, and 6kWh for a bath. I have seen estimates as high as 8.5kWh for a shower. So 2.6 for 2 showers seems very very low to me.
We have rain head showers so that tends to use more water than a regular head. But I shouldn't have to justify our hot water usage. I'm glad you're able to use so little. The iHP looks like a good option for us but I'll be comparing it against several other options in the next video so it'll be an interesting comparison.
In no way was I saying you need to justify usage,apologies if it came across like that. 👍
@@chriss4949 apology accepted. I'm sure it wasn't meant in any way to be a criticism of our water usage. It's always a danger commenting on differences in lifestyle!
Interesting options when considering A2A heating and how to heat DHW - we currently get approx 200-250 days of ‘free’ HW from PV diversion (hardly any in the winter due to the addition of a battery lat year which takes priority)
BTW your explanation of how flat plate and evacuated tubes work wasn’t quite accurate - the water itself doesn’t circulate through them but through a heat exchanger mechanism depending on which type (usually filled with anti-freeze). Also evacuated tubes only have a header tank at the top - the tubes themselves are hollow much like a vacuum flask and have another tube within containing the heat transfer fluid which evaporates and carries the heat to the top to then be transferred into the header tank. They still work pretty well in winter and were all the rage along with thermal stores - they seem to have fallen out of favour over PV it seems but as a supplemental heat source could well fit the bill…
Yes, I simplified the explanation for brevity as it wasn't too important. More important to show that it exists than folks know exactly how it works.
@@TimAndKatsGreenWalk true to some extent, but the benefits are that once you have them installed, there is no additional (electrical) energy input needed (for the most part) unlike the alternatives where you still need a source of electricity - that in itself is the biggest plus point - admittedly on really dull (or snowy!) days the immersion may need to come into play but £ for £ they may actually be the best value solution if you have the roof space...
@@Umski I showed these various options as a starting point for folks to do their own more detailed research if they were interested in any particular solution. I couldn't really describe every detail of every system or else the video would have been excessively long! And there are bound to be many other systems I neglected entirely. Regarding the solar thermal not needing electricity, I did mention it was the sun that did the heating and not electricity, so I think I covered that point in the video, as well as mentioning supplementary heating might be required in the winter.
Using the immersion heater, the cylinder will fill up very quickly with limescale. Like a kettle.
Having 60-65 deg water circulating in the cylinder heat exchange coil, minimises limescale deposition.
Depends on your water hardness and the temperature but yeah, something to consider. Titanium immersion elements help prevent build-up too. Hopefully we'll be replacing our cylinder with a heat pump one next year in any case
@@TimAndKatsGreenWalk
Is it possible to have these heat pump cylinders installed in the airing cupboard?
Yes, although you'd need vents to the outside (possibly via the loft) and you might want to add some sound proofing to the airing cupboard to help mitigate the sound of the heat pump (like a loud fridge). But totally doable.
@@serraios1989 my one is in my garage but it would have fitted in my cupboard upstairs where the old water tank used to live (do water tanks live 🤔) You definitely need access to provide the air intake and exhaust two 6 inch holes. I didnt place it in the cupboard due to my concern about it having some noise but to be honest with the right amount of sensible sound proofing you probably wouldn’t hear it that much and if you have the heating period outside your normal bedtime then you probably want hear it at all
@@TimAndKatsGreenWalk The soundproofing is also likely to provide a bit of extra thermal insulation.
Very useful summary. One or two responses have alluded to this but have you done the breakeven between the existing immersion using night-time tariff (at worst) vs the same on the heatpumps cylinder taking into account the
capital cost of the latter.
On a different topic would love to see in future your analysis of Octopus Go vs Intelligent Octopus. IO sounds better with longer off peak, lower ppkwh and double export (so more like flux...which incidentally my powerwall optimised very well...ie choosing when to export to grid from battery). Currently on Go....and whether the powerwall gets through to 00:30 is extremely sensitive to the solar generation.
If you've seen those other responses regarding return on investment etc. then you'll have also seen my replies to them saying I'm not expecting the heat pump cylinder to pay for itself, I'm not doing it for that reason. I'll explain more in the next video but basically I'm aiming to reduce energy use, not necessarily to save a load of money. Regarding Go vs Intelligent Go, there's not a lot of analysis to do really, Intelligent Go is clearly better in every way, you just have to have a compatible EV or charger to get onto it. Sadly I have neither just yet, but I'm hoping that'll change in due course. In the Spring I'll be doing a quick check to compare Go, Intelligent Go, Flux, and Intelligent Flux, to see if it's still worth switching at that point, so keep your eye out for that video.
Point taken re breakeven...that was my own reasoning when getting solar and battery installed. I also nearly followed on with a mixergy tank but at the time could not find an approved installer to even discuss it! On the Go vs Intelligent Go I agree that the financials are clear and what I should have asked is whether you feel that the "handing control" of your car charging to Octopus have no unintended consequences. Myenergy (they are still testing with Octopus) sent me a data sheet....it's quite complicated and may need current settings on charger changed. Many of your viewers will have gone through this already if they have compatible chargers and would appreciate their comments. @@TimAndKatsGreenWalk
@@KenH-63 yeah, good question about handing over control of the charging to Octopus. I think I'd have to give it a try for a bit to see how it worked in practice. If I didn't like how it worked I could always switch back to Go. But that six hour off peak window would allow us to get another battery and charge up more to support our heating, so that would be too good an opportunity to pass up. I need to run the numbers on that one to see if getting that extra battery would actually be worth it, but my hunch is that it's on the cusp, so if that's the case Intelligent Go would be essential to making that work. Put it this way, I'd certainly give it a try!
@@TimAndKatsGreenWalk I now have IO and it does give the option in the app to switch off smart charging and charge when you want. I understand you must charge using it at least once per month for Octopus to have grid flexibility. Have not heard yet what happens if someone stays on manual.
The second element on your water tank is usually wired in on an economy 7 system (cheap rate electricity overnight).
You can wire the second element up to your Eddi and configure a Top and Bottom of the tank. Eddi will heat top first when boosting / solar excess and bottom when doing overnight heating. Benefit is you only heat what you need. It’s one of several configuration options in the Eddi manual.
We're heating ours at cheap rate anyway, so it's all good.
@@TimAndKatsGreenWalk less heat up time and heatloss when less water required by using top one. lag any warm pipework in the airing cupboard. got our cylinder heatloss down to 68W for a 174L megaflo eco
@@waynecartwright-js8tw the heat loss from our cylinder is about 45W, so I reckon we're doing ok (I lagged the heck out of all the pipes in the airing cupboard).
you could move the wiring on your existing cylinder as the unused heating element is higher up your cylinder so you would be heating less water
True, although we occasionally use more hot water than usual like this weekend when the in-laws came to visit. In cases like this something like the Mixergy system would be pretty handy.
You should wire up the top and use that one instead and do something similar to the mixergy. There is a technology connections video explaining it. Also, I got a T Smart immersion heater that gives you some smarts for around 100 GBP.
Yeah, that's an option but we do sometimes need a bit more hot water than usual (when we have visitors, for example). Hopefully we'll get our replacement system next year in any case.
@@TimAndKatsGreenWalk I fitted a duel immersion cylinder with a change over switch to be able to select either depending on water needs.
Does your current immersion have an adjustable thermostat? If not, you will be able to retrofit a thermostat with a relay for your immersion and you'll save many kWhs by heating the tank to 50 degrees instead of 60 degrees.
Also a very cheap and simple upgrade compared to your other options.
I did tinker with the thermostat inside the immersion until it was at a temperature we were happy with, yes. It's not exactly user friendly and required a bit of trial and error but it's set where we want it now.
@@TimAndKatsGreenWalk Good to know you've already ticked that box! I was set on A2A until coming across your videos and considering the effects of the hot water long term. After a lot of planning, we've finally had A2W Vaillant Arotherm Plus installed and so far, so good.
We are spoiled for choice these days.
@@UpsideDownFork good stuff. Yeah, the lack of hot water with A2A is pretty annoying, and the main downside, but hopefully we'll end up with a decent alternative.
Using a heat pump to charge a Phase Change store doesn't sound that efficient as the heat pump flow temp is above the melting point of the medium , which is above the required water temperature. Heating a water cylinder with a heat pump , the heat pump flow temperature is low while the water is cold & only rises as as the water temp rises so a better average COP is obtained ( in theory) .
The phase change system requires the same temperature water to heat it up as a hot water cylinder, so would work just fine with a heat pump running at 60 ish deg. So the COP would be fine. Even at 60 deg you'd still get a COP well above 2.
We went down the route of the sunamp due to not really having a great space for a cylinder. Its been great. 0 maintainence is certainly a win. Ours is only charged by either PV or more usually cheap rate. But its heatloss is so low I don't think about it. Paring it with a heat pump would make it cheaper to run, the upfront cost of the HP would probably not be worth it unless you were doing A2W
Yup, it certainly fills a useful niche. Now, if they did one with an integrated heat pump...
@@TimAndKatsGreenWalk Yeah, an integrated pump version would have been amazing.
Though IHPs in cylinders feels weird to me as they are drawing the heat from the house to heat the water, which feels weird because airing cupboards traditionally used the heat lose of cylinders to dry clothes or keep towels warm,
@@ungrim97 that's why you use pipes to vent them to the outside (both inlet and exhaust) so that they don't draw heat from the house.
@@ungrim97 here's a good demo, actually: th-cam.com/video/fh6VVF1ayIY/w-d-xo.htmlsi=ycimk_NKXon__0mC
I wasn't aware that some air to air systems can work for water too. Do you know of any systems in particular?
If it can do that, that's kinda cool
So the only one I know of is the Daikin Multiplus system, but it turns out the hot water cylinder is quite small at 120 litres, so not great for larger households. And there is some debate about whether or not you can actually get hold of it in the UK just yet. It might be that we did end up making a sensible choice after all and wouldn't have chosen differently even if I had known about the Multiplus system last year, but there you go. Anyway, worth looking into in case it turns out to be suitable.
@@TimAndKatsGreenWalk Thanks. Definitely worth looking into
I think you also made a fair point at the end ie: the heat pump cylinder making noise which could be annoying when the boiler atm is in my room, in a little cupboard which also acts as a walk in wardrobe.
I do like the idea of keeping the walk in wardrobe, and having a heat pump cylinder outside. I'm not too keen on sunamp largely because of the reviews I've seen against them and them being fairly vague on their website
BTW have you looked at a Zypho or similar? The idea is that they have waste water heat recovery which further helps save your DHW usage
@@waqasahmed939 you'd probably want the heat pump cylinder in a garage or similar, rather than outside. I'm not sure how weather resistant they are (electronics and such) and they would lose more heat when outside too.
I have looked into the Zypho, looks interesting, but not something I'd install unless I was remodeling the bathrooms. One to keep in mind for such an eventuality though.
@@TimAndKatsGreenWalk That's fair. I do only have a small (uninsulated) garage too. I'm with you RE: only getting a zypho if remodelling. Otherwise they seem expensive as a one off
I did however switch from an electric shower to a smart digital shower. I've got an en suite that already had a mixer too, and interestingly I found zero pressure drop when replacing the electric shower for a smart digital shower. I think the digital thingy regulates the pressure somewhat which is very useful when I don't have a cylinder .
My initial rationale was :
It's unlikely that I'll use the en suite at the same time as someone in the main bathroom.
The guy before me was an auto electrician who wired the shower and lights together on the same circuit and that kept tripping my fuse.
I was told that the wire was just within tolerance for the shower but not also for the lights too, and I figured I seriously reduce the risk of my house burning down due to a wire getting too hot and I reduce running costs if I move to a mixer
I bought the smart digital one because it was £200 more and I thought that's not bad in the grand scheme of things
I've now had a shower whilst the other main shower was on, albeit rarely, and I still found zero issues. That's a nice additional benefit
I found out about the zypho later on however so if I remodel, I'll pop that in
@@waqasahmed939 goodness me. Yes, I can see why you'd want to change it. It's always tough to decide what's best to do. Good luck with whatever you decide! Although at least the digital shower seems to be working better for you.
I am just about to start a major renovation on a 1950's bungalow. I am starting off with a wrap around extension and a dormer in the roof. The front of the house will have external insulation fitted and as it semi-detached I am also going to include some insulation on the adjoining walls. The roof is East West just like yours so I will have 6 in-roof panels on the front and 6 panels on the flat roof of the dormer at the back. I have designed in a plant room, as the garage is being demolished, and that will have a Mixergy tank, a tesla battery, connections to the underfloor heating from the ASHP and an MVHR controller along with one or more new consumer boards and a power supply for the car charger.
My question is this, can the ASHP support the Mixergy tank as well as the under floor heating? or should I try and power the Mixergy tank from the solar. I think I understand most of how everything works individually but it is how I combine the various elements that I get a bit lost (also planning on having the Harvi & Eddi). Your thought would be very welcome p.s. I love the channel.
Sounds like a great project, but there's one adjustment I'd suggest. You shouldn't need the Mixergy tank at all as most A2W ASHP systems will come with their own hot water tank, which will run from the heat pump too. So in other words you'll get both heating and hot water from the one system. If you're heating your water using the heat pump (which is what I would recommend) then you shouldn't need the eddi for solar diversion either, as it's much more efficient to heat the water using a heat pump (at 300% efficiency) than using direct electrical heating via the immersion and eddi (only 100% efficient). You could then export that excess solar instead using a good export tariff such as Octopus Flux in the Summer (and then switch to something like Go or intelligent Go in the Winter when the excess solar dries up). Whenever you're heating anything (home or water) then a heat pump is always the best option. I hope that makes sense.
Thank you so much for the heads up, I hadn't realised the ASHP came with it's own hot water tank, I was thinking of the Mixergy as It will only be me in the house most of the time and I liked the idea of only heating as much as I needed, presumably the standard tank will be fully heated. My reason for doing this is to have minimal cost in my old age and I only have the money now and when it's gone it's gone. Having read some of the other comments not having the Mixergy would also save on the servicing. Have I missed any tricks anywhere else?
@@christinewhite3749 so you'd probably find that a heat pump heating a full cylinder will still be significantly more efficient that a Mixergy tank heated only halfway. Although, you could probably get a relatively small cylinder to go with the ASHP system (120 litres, say), in which case you'd get both benefits. As for other considerations, the only other thing I'd suggest is taking a look at the GivEnergy All in One battery, which has similar specs to the Tesla Powerwall but is a lot cheaper.
a suggestion?
you mention Tesla battery
if you follow Tim's great suggestion of a GivEnergy battery, maybe consider TWO batteries? (say, 20KWh-24KWh). Might *still* be cheaper than Tesla PowerWall!
my suggestion is based on the substantial eventual size of your home, to maximize self-consumption in summer and maximise off-peak charging in winter.
it depends on your home and EV's consumption, and generation, across all seasons.
installation costs are a *SUBSTANTIAL* proportion of the final cost; installing two at the same time is likely to be considerably cheaper than two installed separately.
perhaps look to the associated GivEnergy EV charger for benefits from them being able to 'talk' to each other so they are both smarter
Thanks for adding to the conversation - I did look at other batteries but unless I am mistaken the Tesla seems to be the only one which can power the house in a power cut, others just let you have a couple of sockets so you can boil a kettle, we just don't know what the future holds and I would just like this little extra security, If I am mistaken please set me know.
Trying to decide between mixergy and sunamp at the moment…
Mostly because of the boiler upgrade scheme requirement that the same heat pump has to do hot water as well…
It's good to have options at least!
I think the government will upgrade their schemes to take on board standalone ASHP water cylinders and A2A setups in the coming year as they adapt to the various options out there for people.
@@bobbazley5376they might, but I don’t see it before an election, and I can easily see my boiler not lasting that long.
Check the reliabilty of both before purchasing.
@@tlangdon12Sunamp seems to be very confident in the reliability of their produits. I heard their CEO say they expect 20-30 years of service life
agree with being more efficient, but less is not always more…we went down the Fischer Aquafficient (210l) heat battery for simple reasons really: 1) size: no cylinder, moving parts whatsoever essentially space saving and a third of your cylinder size 2) zero noise & no annual servicing 3) compatible with solar & off peak charging….we literally never use the 210l available that is fully available and it recharges overnight (cca 5kW)….considering its off peak charging its a no-brainer to go down this route compared to 40-50db continuous noise and tripple the size solution just to get extra 3kW?with no real financial impact…
3 kWh per day quickly adds up. I'm glad you're happy with your Fischer system but that doesn't mean it'd be the best option for everyone. The point of this video was to show a sample of the available options so folks can make their own decisions based on what's important to them.
The 5kWh to heat up was my main concern with the Sunamp type setups. It’s the same direct electric heating of my old standard water tank. So any saving on usage is a good return. What was the cost of your unit to replace our hot water as the Sunamps where quite expensive. Agreed they are not as big in size but they do more or least take the same footprint so you gain more shelving space but thats about it. Agreed you can charge at cheap rates with a solar setup in the mix it helps during the summer will still take less to heat up the tank and I can schedule it to run at cheap rate times as well but it takes longer to heat so without solar I would use some non cheap rate tariff. With battery I can use that to offset the various rates and timings by power it from the battery when its be charged up by cheap rate electric
@@bobbazley5376 battery itself for the 210l v9 is 10.5kW capacity, but we never managed to fully deplet it…usual off peak charge midnight onwards with 4.5p. And yes if you have battery can be used but I dont see any reason as you already charge off peak or PV so daily grid is not needed. hot water is instant and box itself is never warm or hot.
@@TimAndKatsGreenWalk 3kW adds up, it does, so will your annual servicing cost so this argument is irrelevant…p.s. you should not take things personally 🙂 if you want a chunky noisy box-of course, the choice is yours
@@robert_minarik I did say I was going to install it in the garage out of earshot. My priorities are different to yours, simple as that, there's no need to suggest that my choice is inferior to yours somehow (I'm certainly not suggesting your choice was wrong, it's clearly something you're happy with and I'm glad for you).
Are you considering a thermodynamic panel? Instead of the outside unit you have a panel on your roof or wall. I haven't seen much on TH-cam about them lately though.
You mean like the solar thermal option I mentioned, or are you referring to something different? I think I'm pretty set on the heat pump cylinder at this point but if there's something I've missed I'd be interested to know.
Interesting.. Just for clarity and assuming a new water based ASHP where being fitted the ASHW-cylinder would not be needed? Would there be a differential between SCOP of an external heat pump plumbed to a specific compatible cylinder and that of a ASHW-cylinder? For some reason I had it in mind that the external ASHP only heated a hot water tank at a SCOP of 1 🤔
The SCOPs should be similar regardless of where the heat pump is installed (as long as the air is vented to and from the outside) . So an external heat pump would still heat a cylinder at a SCOP of 2.5+, maybe higher in some cases. The main advantage of the A2W system is that you then only need the single external heat pump, which would provide both space heating and water heating. Having opted for A2A instead I'd need that second heat pump for the hot water, unfortunately. In either case you need a cylinder to store your hot water, heat pumps can't provide hot water on demand.
For the ASHP cylinder would you not want to draw in air from inside? This would be more efficient as the air is warmer. The vent will want to go outside as the air will be cold, although in summer it would be good to be able to direct thisninside as well for cooling
So you can vent in a number of different ways and certainly in the summer being able to vent the exhaust cold air into your house can be beneficial and certainly doable with the appropriate pipework and switches. But you don't really want to draw warm air from your house in winter as you then have to replace that warm air with your heating system, so you don't really gain anything overall, if that makes sense.
Additionally, if you take air from inside the house envelope and exhaust it outside then you create a lower pressure inside the home. This will create draughts anywhere where the envelope doesn't seal perfectly to the outside. They may well be just where you don't want them! For example, the vented area under your ground floor (if you have such a thing) might become your air feed into the house. I am not sure I would want this musty, stale air as my house intake.@@TimAndKatsGreenWalk
@@Ben-gm9lo indeed. Best to have both vents going outside.
would be like running a cooker hood 24/7 just dumping your heated house air outside.
Hi Tim thanks for another great vlog. I to didn’t know you could heat your hot water with an A2A system so I am looking at a Mixergy tank. I am told the heat pump on top of the tank is quiet?? So would be suitable for an airing cupboard??
The problem with all this change we are doing I have found little advice/ information on which direction to go.
So have relied mainly on TH-camrs like yourself to make my decisions and I thank you for that and sharing your journey.
Best regards
Simon
Well, the heat pump on top of the Mixergy cylinder is not exactly silent, I think you would notice it. It'd be like having a particularly loud fridge in the airing cupboard, so you might want to consider some sound proofing treatment to be sure. Unless you can install it in a garage, say. Although another viewer did mention that apparently you can install the cylinder and heat pump in two different places, connected with the relevant pipes, so you might be able to install the cylinder in the airing cupboard and the heat pump somewhere out of earshot. I've not verified this just yet, but I'll be getting in touch with Mixergy to confirm. In either case you would need venting pipes to the outside for the heat pump, so that's something to bear in mind too.
@@TimAndKatsGreenWalk maybe I could connect it to my existing ASHP as I have a spare outlet on it?
@@simonperkins345 good question, that's not something I know the answer to for sure. You'd have to contact your ASHP manufacturer to see if you can do that.
Tim, your thoughts on this being a bit of a diminishing return?
5 units at 9p x 365 days approx. £165 p.a. for hot water
reduce that to 2kw a day and your cost p.a. approx £65
A saving of £100 a year - less if you manage to end up on intelligent
So isn't a further option Hot Water option simply to do nothing for the time being, perhaps even find a way to export just a little more and perhaps easily cover that £100 by other means?? Moving to Intelligent alone would cover that saving. I know, cars and chargers are the Intelligent issue.
Just a thought??
All the very best
Mike
It's a valid observation, for sure. However my main priority isn't cost saving (although clearly that would be nice too) it's energy saving. I realise I'm probably in a minority but as long as it's not unreasonably expensive to do so my aim is to reduce my energy consumption and increase my energy generation to the point where I'm a net exporter. I'm not really expecting to get a "return on investment" with this, I'm simply trying to find a way to reduce the amount of energy we use to heat our hot water. I'm sure a lot of people would consider that a silly thing to do but that doesn't concern me. We don't have kids, I have a decent job, we have the cash to spare, and this is what I consider a reasonable way to spend it. If I can help provide some information for a few folks who might be considering doing something similar then so much the better. Hopefully that makes sense.
@@TimAndKatsGreenWalk Thanks for taking the time and effort to make all the videos and replying in this case. It wasn't a hater or detractor comment at all and if I didn't ask it then someone would have and probably less sympathetically 😉.
I know you don't surplus divert with Eddie as it doesn't suit your plan, but I can't get over how we just have all the hot water we need free from the sun courtesy of Edward! I started recording my peak boost sessions to see how efficient Eddied hot water had been, but soon stopped as it's probably only 10 - 20 times in 18 months.
I'll be very interested to see your research on the Heat Pump tank you've chosen. Did start to muse over something similar after watching this. Our hot water tank looks uncannily like yours and thought I could draw air from the loft space 1m above, but quickly realised all that would do is to make the loft colder and probably increase thermal loss through the ceilings. Perhaps there is a soffit (the under side of the roof between wall and gutter) vent available?? Draw air from the south side of the house and vent to the north???
Anyway our timeline is first to treble or more our solar generation to something in excess of 10kw.
Keep up the good work, looking forward to the next video.
All the Best. Mike
@@oldgitflying yes, you're right about the loft space, it would decrease the temperature and therefore the heat drain from the house, so ideally you would vent to the outside. But if your loft is well ventilated anyway it might not be a big problem to just put both inlet and exhaust into the loft, or else vent through a roof vent, as you say. I expect there are some neat solutions for this.
I don't mind at all you asking the question about investment return, it's a very valid question. I guess the main reason for this video is to show what options are available should someone need to replace their hot water system through age or failure, in which case you may as well get an efficient system as a replacement and the "return" part of that is less important since you'd be replacing it anyway.
Thanks for the video, very informative! I’m in the process of looking at air-to-air systems, can you tell me which ones do water as well? I haven’t been able to find any so far.
I think Daikin do an all in one system? Don't quote me on that though. They're certainly very rare in the UK, much more common on the continent. Perhaps that will change over time as more folks look to get systems like this.
I'm not in the UK but have a Hitachi Yutampo Twin. The Daikin one is called MultiPlus.
@@BenIsInSweden ah yes, that's the one I was thinking of, thanks.
Nice insight to the options available . Seems like a very small return for an expensive investment, have you done any calculations on return of investment if using off peak tarriff in winter and free to heat with solar in summer
Yeah, it's not the best "investment" for sure, but that's not really my aim here, I'm mainly trying to reduce our energy usage. If you have a good export tariff in the summer (Octopus Flux, say) then the opportunity cost for export is pretty high (20 p/kWh ish) so saving those kWh to export rather than heating your water is actually pretty beneficial. Even so, I doubt you'd pay for the kit in a reasonable time. Still, I present these options for those who might be interested. And if you have to replace your hot water system anyway (due to age, or failure) then it makes sense to do so with an efficient replacement.
I think mixenergy have control over the cylinder so they can dump heat into it when required at certain times and they charge to have someone come out to service every year also
Hi Tim, We currently have a 5.8KW solar system with a 5.8KWh battery. We're currently on Octopus Intelligent Go and are very happy with the tariff. I have set it up so it draws from the grid at night during low cost so that the solar feeds in during the day. We have seen the offerings of Air Source Heat Pumps with the government subsidy, meaning that te quotation we received from Octopus to fit an entire central heating (existing radiators) and hot water was just over £1000. Our house is relatively new build and has cavity wall insulation and good loft insulation. I was wondering what your thoughts on a ASHP in a four bedroom property would be. Would it actually save money? Given that it would be greener, for sure, than our current Gas system, the only concern I haev is that it would cost more to run than gas during the winter. I don't necessarily want to take the plunge if it's going to be costly to run. Our gas combi boiler is nearly ten years old, so it may be that that will have a failure at some point.....! Any thoughts, please? Thanks!
If you were on a standard tariff with no solar or battery system then running a heat pump would work out similar in cost to a gas boiler. With solar and battery to support it, when combined with IOG, you should find it a fair bit cheaper to run a heat pump than a gas boiler. You might find adding a bit more battery capacity helps too, as that extra battery can be used to effectively run more of your heating at the off-peak rate. We have 14 kWh of battery and last Winter we ran our heating almost entirely using off-peak power, all except the coldest days. However, even with a modest battery you should find that you can cover a good fraction of your heating in the autumn and spring with off-peak power or solar. I hope that helps.
You might find this of interest too:
th-cam.com/video/q1tYCenxb2M/w-d-xo.htmlsi=lgu_4O-EK5Um3ek5
@TimAndKatsGreenWalk thanks so much. At the price they've quoted, it seems to make perfect sense. We can't really afford another battery as well as a heat pump, but my head is fairly convinced about the potential savings. There aren't many real-world experiences out there at the moment, so you giving an answer is very helpful. Thank you!
@@Simonstunell1974 no problem. It's worth seeing how you get on in the first winter with the heat pump. You might find the amount of battery you have is sufficient. In either case you'll have some data to work with then.
What about the ZEB, it does central heating and water, very little change is needed if any, remove the boiler and plug in the ZEB. It would be great to get your thoughts on the ZEB.
The ZEB doesn't currently do hot water, but they're working on it. As and when they bring out that 'combi' version I might add it to the list, but for now it's central heating only. I wouldn't personally consider it for our situation as it's not as efficient as a heat pump based system, so wouldn't help us reduce our energy use, which is my main aim. It's definitely a good solution for some homes though, no denying that.
My understanding is that ZEB will do hot water but only if you have a hot water tank. And as you say they are working on a combi version.
@@alanfoulkes9383 I thought it was central heating only right now.
@@alanfoulkes9383 ah, no, you're right, it can heat your hot water cylinder too, my mistake.
A ZEB is just an electric heat store. IIRC it's just a lump of concrete that you heat with electricity when it's cheap, and then extract that heat later in the day. That makes some sense for heating your house (if it's a lot cheaper than a heat pump), but a hot water tank is already a heat store for an immersion heater.
Quick question - so a 0.850kW electrical heat pump would generate 2.89kW of heat with a CoP of 3.4 (iHP Mixergy figures). The one you installed in your home provides enough heat?
Yes, we have plenty of hot water. It tends to run at about 400W though, so takes a few hours to heat a full cylinder of water.
Thanks for the prompt response.
I live in the US with an old gas powered hot water boiler and cast iron radiators that require very hot water to heat the house. Thinking about the possibility of either replacing the boiler with a Sunamp (if possible) or using Sunamp to heat a large tank of water and somehow use a heat exchanger in the tank to heat the water - instead of the boiler. How hot can the Sunamp heat the water? Any suggestions? I also am thinking of getting PV panels. Thanks, and great video!
The idea behind the Sunamp is to be a replacement for your hot water tank, rather than using it to heat a hot water tank. It's the Sunamp that then provides hot water to your home by passing cold water though it so that the heat is transferred to the water. The water comes out at 60 deg C from the Sunamp. The Sunamp won't provide water to your radiators though, it's only designed to provide hot water out of your taps etc. To fully replace your boiler you'd need a central heating replacement such as a heat pump (air to water or air to air, for example). Heating a home takes significantly more energy than heating hot water, so a Sunamp wouldn't cut it even if you did manage to hook it up to the radiators.
@@TimAndKatsGreenWalk Thanks Tim! but if I did replace my boiler with an air to water heat pump, could the water temperature be higher than 60 deg C, which would be needed in the cast iron radiators to heat my home?
@@marksTips466 you might be better off replacing your radiators at that point too. Most A2W HP systems work best running closer to 50 deg C, or below if possible.
I was going to suggest that a factor to consider is that the ASHP can run efficiently continuously - so your cast iron radiators would be "always on". In that scenario, could you keep the cast iron radiators? Simpler and lower cost.
But on reflection a heating engineer can perform heat loss calculations and tell you the size of radiators needed - whether they go on/off or run continuously.
In the UK, often even modern steel radiators might need to be enlarged when switching from boiler to ASHP. So the cast iron radiators may need to be replaced.
in your post you don't say where in the US.
if cast iron radiators*DO* need replacing, and you also need A/C in summer, then perhaps A2A cooling and heating might be a smarter choice?
Check on the reliability of the Sunamp before you buy.
We use Tesy Heat pump hot water cylinder
Ah, another model I hadn't heard of before. Thanks for letting me know!
I will try to get over my disappointment that you weren't doing cross stitch on a unicycle .....let it go me ! 🙈
I'm still not sure where A2A and grants are even though someone did say that combined with a HP water tank you could/might qualify. 🤔
So in the meantime I did sign up to trial with heata . (Hopefully I'll be selected) This is the data processing centre attached to the tank. Saw this fullly charged live. Might be worth your while 🤷♂️
Yeah, I saw a video on that data centre thing. Not something I'm considering but an interesting option, for sure. So it seems that A2A *doesn't* qualify for the BUS even if it comes with hot water too, which is a shame. A bit of an oversight in my opinion but there you go. Perhaps that situation will change but I wouldn't bet on it.
We have just had a hybird A2A/A2W system fitted in our bungalow that did qaulify for the BUS grant! Daikin Heatpump that runs to a unit that spilts it to a hot water tank and then water to 4 fan units in the loft that can run hot or cold air ducked into every room. Was a huge amount disruption but we had a dead gas combi and rusted out radiators. We have lost a fair bit of loft space but no radiators frees up a lot of wall space inside the property. We are a 3 bed bungalow and it cost us £8 after the old £5 BUS grant @@TimAndKatsGreenWalk
@@simoneisgod ah, very interesting. Sounds like a great system. Ok, so it seems my understanding of the BUS isn't complete.
I'm currently weighing up options for replacing a gas combi boiler doing water and space heating (and maybe gain aircon in the process if I go down the A2A route). Thanks for this video, a helpful addition to my research.😀
Regarding the high-power (and relatively expensive) electric combi boilers, are they not sized as full replacements, to cover both hot water and radiators? I was under the impression that much smaller and cheaper units could be used just to heat the water (possibly separately for kitchen and bathroom), if space heating was being taken care of separately. Any thoughts on this?
Yes, you can get smaller units for hot water only but they still require very high power to create that hot water quick enough, and that will result in peak rate power draw so will end up more expensive to run than storing your hot water in a cylinder heated with cheap rate power (assuming you have the space for it).
@@TimAndKatsGreenWalk I see what you mean. I'm in a 1-bed flat so space is at a premium; I had given some thought to Sunamp, but was thinking that electric batteries (rather than heat batteries) would offer more flexibility. But I guess not if they aren't capable of supplying power at the required rate.
My options for replacing the combi boiler are likely to be constrained; I'm on the 3rd floor with no balcony, but I do have a loft. I'm guessing I won't be able to get an external unit installed anywhere. I have seen that there are entirely internal A2A units available, for which you basically drill two holes in the wall in order to draw outside air through the unit.
I've also been considering far infrared panels for heating (forgoing the aircon).
I confess I've not entirely ruled out just getting another gas boiler.😕
@@colinmcconnell827 yes, that is tricky, I understand your predicament. A battery like the GivEnergy All in One can output at 6 kW, so that would be almost able to cope with an electric boiler running at 7 kW, say (which is similar to an electric shower power rating). But then you're spending £6k+ for that, and it takes up room, so something to factor in. It does sound like a Sunamp type system might be a decent option in your case for hot water. Regarding heating I'd certainly be interested to learn of any A2A systems that are entirely internal. Of course you then have the issue of the heat pump itself being inside and therefore being more audible (like with the heat pump cylinders I mentioned). In a flat that might make it quite intrusive. If the whole building could come together to implement a building wide system that would be ideal, but as always much trickier to organise!
@@TimAndKatsGreenWalk Sorry, I posted a reply yesterday which disappeared into the void; I think TH-cam may have thought it detected external links and not allowed it as a result. I'll try again, totally link-free -
The internal A2A units seem to be mostly marketed with the terms 'condenserless' or 'twin duct'. You can find TH-cam videos demoing them, as well as websites from manufacturers and sellers. Some brand names are 'Powrmatic' and 'electriQ iQool'.
Looking at them again, I notice that they are marketed as air conditioners with a heating mode. This may be connected with comments I've seen that they don't work well (or maybe at all) when the outside temperature gets below 5C. So, as well as the noise, that might be another reason to avoid them.
As I said, I have a loft space. Most sources I have seen have said that it is not viable to install a condenser in a (suitably ventilated) loft, but I have seen one or two articles suggesting it can be an option. If could make that work, then I could potentially end up with an ideal solution where all the bulky, noisy stuff is hidden away and I just have a few vents in the ceiling. Have you come across anything like this?
@@TimAndKatsGreenWalk You can get entirely internal heat pumps - they wall mount with air intake/exhaust at the back which is then drilled through the wall. Externally all that is visible are some circular covers. My inlaws have two for heating/cooling their house, they seem to work well (scop of 3) but might be too noisy if you are in a comparatively small space.
I'd stick with what you have, just make sure the controls are always pulling energy when its cheapest/free. It's a shame the multi-split A/C guys don't provide a solution for water heating, you could imagine a fairly simple heat exchanger on one of the loops, with the right set of valves in summer it could dump heat from space cooling into the cylinder. I'm sure its coming and it might make me look at a refrigerant based system over a water based one when it comes.
There are some A2A systems that do effectively what you suggest, but not many, sadly. Daikin Multiplus is one such system. I didn't know about that when I first looked into A2A last year.
@@TimAndKatsGreenWalk Also the Samsung TDM+. The Daiken Multiplus has a 90/120l tank, which seems well below the MSC standard for tank size. The intent seems to be more flats than houses. So the TDM+ tank is too big for a UK domestic hot water cupboard, the Daiken multiplus probably won't allow two showers in a row, and would require daytime electric or battery cover to reheat if there is a brake between the showers and you don't need heating/cooling while it's doing that. I know the focus is on tanks, but I think you're beating yourself up for not going for an A2A+DHW option that doesn't really exist!
@@stevescott9289 perhaps you're right! I hadn't realised the Daikin tank was so small, that definitely wouldn't have covered our needs. Might suit some folks though, as you say.
@@TimAndKatsGreenWalk Only thing I'm trying to work out is if a A2A+DHW system could qualify the the Boiler Upgrade Scheme. Our house is 1980's warm air, which is unsuited to A2W (We have no radiators).
@@stevescott9289 this is a tricky question to answer and I've been unable to fully get to the bottom of it. On the BUS website it says (or said at one point when I last looked) that A2A didn't qualify even if it included hot water, but then another viewer said that they were able to get the BUS with such a system. Perhaps a canny (MCS registered) installer could make it happen but from my experience most "regular" AC installers know nothing about it, so it'd take some research to find a suitably qualified and knowledgeable installer.
Changing your current setup for hot water will never be cost effective. Better to spend money on more solar if possible. A quick change is to wire the top immersion heater instead of the lower one will mean you are heating less water.
I'm hoping to do both but in either case I'm not expecting it to be cost effective. I'll explain more in the next video.
Solar panels will COST you money (typically), they don't save money - it's a myth.
Hello Tim, I am in the midst of taking quote to put mixenergy and then move onto putting heat pump, is this ok and more efficient than the cylinder that comes with heat pump?
I'm not sure what you mean when you say put in Mixergy then move onto heat pump. Do you mean getting an iHP cylinder, or a regular Mixergy cylinder?
I think I've worked out what you mean. You are getting a quote for a regular Mixergy cylinder but plan to get an air to water heat pump heating system installed later. Is that correct? If that's the case then I would suggest not getting a Mixergy cylinder as you will get a new cylinder with your air to water system which will work better and be cheaper than a regular Mixergy cylinder. There is certainly no need to get a heat pump cylinder (with the heat pump as part of the cylinder) if you are getting an A2W system. The efficiency is about the same for both.
@@TimAndKatsGreenWalk yes that makes sense. Thank you
Wont the servicing cost of a HP cylinder negate any savings you make ?
It's the energy saving that matters to me. See my pinned comment for more detail.
ive just has my air to air serviced and it was a lot more than i anticipated so thought it was worth noting
@@robpatterson754 same, as it happens. I'll mention cost implications in the next video.
You have done so much up until now that you are pushing a case of diminishing returns. If net exporter is your goal, have you not looked into custom built Evacuated Tube Collectors to mount on the house front in that Apex area with the cylinder in the loft behind them for hot water. Like I said, custom....so it looks good and becomes an external house feature. Years ago people thought solar panels were strange and today they are everywhere.
Oh, I totally appreciate that it's not necessarily worth it in terms of cost doing this extra stuff. But I'd like to do it anyway (gotta have a hobby, right?) and it gives me something to talk about on the channel! It's a bit of a rabbit hole, all this, and in some respects I do this stuff because I find it all really interesting and figured it was worth sharing some of the research I've been doing. Regarding the evacuated tube collectors, that would certainly be a lot more expensive to install than a heat pump cylinder but I might investigate that option at some point in the future, once I've run out of other stuff to do!
@@TimAndKatsGreenWalk Check out UK company Naked Energy. They have an interesting range of evacuate tubes for solar and hot water.
Interesting tech. I'll keep an eye on it.
Very interesting indeed , listening to you just tells me how little I know in regards to all of this modern stuff for want of a better word on the market , I like the idea of getting rid of my gas and getting a heat pump , but never seem to be able to find any information about the cost between a heat pump and a gas boiler , hear lots about how efficient the heat pumps are , tend to hear figures such as oh the heat pump is 160% or 400% more efficient well Great but how much is the cost from October to March month by month with cost , it’s like as though the true cost is being hidden, not the cost of the heat pump but the cost of running it , all people say oh it depends on what tariff you’re on yes that’s seem to be a cop out as I see it , there has to be some kind of chart or ball park figure yet nowhere can one find this information. Yes you will need a whiskey to get through this message at least you will be warm in the inside.
The simplest way to do the calculation is to look at the SCOP (seasonal coefficient of performance) of the heat pump. A SCOP of 3 means it generates 3x as much heat as the electricity it uses. A gas boiler is about 80-90% efficient so effectively a SCOP of 0.8-0.9. Gas currently costs about a third as much as electricity (give or take), so a heat pump will cost about the same to run as a gas boiler. Then the tariff comes into it of course, but there's your ball-park figure. For us, we're able to run our heating using solar and battery (which has been charged up at cheap overnight rates) so it does then make it significantly cheaper than a gas boiler, and the water can be heated overnight too, using that cheap power. I hope that helps a bit.
@@TimAndKatsGreenWalk That’s probably the best answer I’ve ever seen , I think that whiskey has reached the logical nerve. I’ve watched a few of your videos which are very good by the way , I don’t have the money for solar or battery set up, just trying to get warm in the most efficient way and my biggest fear is not being able to afford to run the heat pump , irrespective of the efficiency of the heat pump compared to gas boiler I have this underlying concern it’s going to be three times more expensive with the bills. If someone could prove to me that here are the bills month by month from October to march comparison and there’s no difference, I would put my order in tomorrow, but my gut feeling is they can’t and it is three times more expensive to run, I’ve started to look at wood burners now which is crazy and even I think it’s crazy that I’m looking in that direction, maybe the way forward is for the electric companies to those who buy a heat pump don’t have 15% of their bill to pay for the green agenda that way the cost of running the heat pump would be more in line to those who have gas bills .
Running a heat pump is definitely not three times the cost of running a gas boiler. It'd be comparable, maybe a bit more, maybe a bit less, but certainly not three times more!
@@KavanOBrien there are various factors at play here you will use more electric than you normally use during the winter months as thats due to using an ASHP to do your heating (be that air2water or air2air) but to heat water within an ASHP is much more efficient than heating it with gas for the same energy input. The main issue is ASHP have a lower heat output so radiators may need to be upgraded and just doing insulation will improve the heating. The main point is that everyone’s house is different and their existing services are different and the need to upgrade or replace is different. I had oil I wanted to replace that with electric only solution as I have solar and Battery storage which absolutely reduces my monthly costs and offsets the high rate tariff periods. There is a payback period for my solar and battery but it will at current rates will be paid back full in 8 years total (ive had just under 3 years so 5 to go) but that is assuming prices stay as they are which I just dont see happening so when it utility prices go up then my return period will come down. I dont think a wood burner is viable as you still need to get a wood burner, then the wood and the time it takes to setup and clean. Unless you have free access to wood and the right type of wood not something that will burn in minutes.
@@bobbazley5376 heard every story known to man and beast, I live alone only have an old age pension coming in but would still like to do my bit for the green agenda, don’t have money for solar or battery storage or update radiators , it might help people in my position if the electric companies took off the 15% of the bill for the green agenda for those who are trying to do their bit ,
I am all in favour of A2A heating but why did you get rid of your gas boiler and then install such a massive tank? Doesn't make sense as heating water by electricity is far more expensive than having shower with a combi. What else do you wand hot water for anyway as I'm sure you have a dishwasher and washing machine both of which run on cold water. PS the top immersion is so you can heat a smaller amount of water which saves money
The tank was already there as part of the existing system, we didn't install it. It costs us less to heat via the immersion than the gas boiler because we do it using off peak power. I've got plenty more videos that cover all of this stuff, so go check those out.
Oh exciting update, gets cup of chia and cinnamon roll to watch ……..
Have you investigated ways to install a heat exchanger that removes the heat from the wastewater and heats your house so that heat is not wasted. 🤔
I've seen a couple of options but realistically it's more disruption than I'm willing to undertake at this stage (would require ripping up the showers etc. for example). If we were to ever need to do work on the showers/bath then I'd look into getting something like that retrofitted at that stage, since it'd be easier to do while other work was going on.
@@TimAndKatsGreenWalk Yeah. They are a no-brainer in new constructions but pretty expensive otherwise. Although I think mentioning them in your videos will inform people of their existence
@@johnzach2057 I'm sure I'll get around to doing a video about them at some point, but I've got a very long list at the moment!
I wouldn't change what you have apart from wiring the top immersion you will never get your return on investment an immersion costs £20 changing your unvented cylinder for something else will cost thousands im a heating engineer of over 30 years and ive seen new hot water systems that are all singing and dancing and they don't last
Although what you say is valid, I'm not actually doing this for a return on my investment, my main aim is to reduce our energy usage, as long as it's not prohibitively expensive to do so (see previous video in this series linked in the top right corner). I'm sure a lot of people would find that strange but there it is.
Ok mate
Hello Tim, I have an Ecocent version of your favoured ASHP on tank. It’s excellent! Very efficient. It draws from the landing, unlike your plan and vents out from the attic. It’s not that loud. We only hear it when we walk past the airing cupboard where it is. I recommend, but, like @buddywheels, if I had to replace it, Sunamp really interests me. Only issue with Ecocent is that it needs a pump to capture condensation. It recently went wrong and dropped water into the downstairs shower room. It happened during Storm Ciaron, which freaked me out; how could rain come in sideways and not from the roof?! Other issue is that it’s not great at handling a houseful. We are normally three but when daughters and spouses come down from London, it runs out and takes time to recover. Yes, there is a boost but fast it is not. Alex
PS; like you we have a split system. But unlike you, central heating is a pellet boiler. In my defence, it came with the house. Apart from its lack of eco credentials, it’s effing hard work!! I dream of a system where I don’t have to feed it everyday and riddle ash!! 15kg of pellets a day!!! When my ship comes in it’s going!!!!
Ah, I hadn't heard of the Ecocent version, I'll add it to my list for the next video! I hope you were able to get the pump fixed.
The way you describe it, it sounds like it sucks heat from the heated space of the building, and then vents this into the loft space (aka the uninsulated space)? Surely thats not right?
I also have an Ecocent 300. It works very well as it gets its air from the MVHR system which is warm and so improves efficiency. You would think this would cool the house but that does not seem to be the case. I agree it is slow to heat the 300 Lt of water when we have visitors but you can set it so it runs all the time to maintain a programmed temperature. When there is just 3 of us in the house I have it run in the night when we have cheap elec with a top up during the middle of the day. The main issue I have with the system is the terrible service from ESP. These type of integrated ashp/dhw tanks are very popular in the US. If you want one just steer clear of ESP
Yes, it doesn’t seem to cool the house. And it was explained to me that it was more efficient, as you describe. Thank you for the operational tips; v helpful!!