Thanks for the vid. I’ve had a Daikin Altherma 3H HT ASHP & Mixergy h/w cylinder since April 21 too. 220m2 2002 bungalow. We’ve had solar PV since 2012 with a Solic 200 electric diverter to heat h/w. I’ve doubled loft insulation to 300mm, triple glazed (we have a lot of windows), changed bathroom extractor fans to ones with covers. Even put covers over key holes to reduce drafts. We used just over 4000kWh in a year. With a SCOP of 3.67 using a Nest controller. I’ve changed to using Daikin weather compensation on the ASHP since April 22 to compare efficiency. My predicted electric usage was 7300kWh 😮 via the MCS estimates. My wife says home was warm enough. We matched oil boiler running costs to ASHP. Sorry forgot to say we didn’t change any radiators, have 12mm microbore drops to each radiator from 28 or 32mm mainline pipes in the loft. Check out my installation on Ecobubl TH-cam channel. I will watch you changes with interest. I’ve been gradually turning down the ASHP flow temp. And weather compensation will impact this more, but run my external unit more. Thanks again
Thank you so much for putting the stats out. Very helpful. I have heard the more the heat pump starts and stops then lower the cop. Looking forward to see more.
This is a far better comparison for people interested in an ASHP as it a direct comparison for 2 different souces of heat. The mitigation being that it can be improved by under floor heating. There are too many people on youtube showing heat pumps working well with a std home heating systems (radiators) and they just dont. I would guess your summer COP is low because it always will be when producing only hot water (60C+) the compressor is working at its hardest. But its true for all consumers and therefore a fair statistic to note.
How did you chose your flow temp? Did you run low and creep it up if you were cold? The design temp is usually for -2 in the UK. So for spring and autumn you should be able to run much lower. Maybe play with your weather compensation curve. We have a radiator and ufh mix with part insulated terrace house and get a cop of 4 or even 5 during warm ish oct and Sept.
Solar thermal appears to to give lower cop figure... Sounds plausible , If you have a heat meter on the heap pump flow & return pipes. The solar could give you all the hot water & the heat meter record nothing & record a COP of 0!). Should be possible to put a simple energy meter on the solar thermal controller ( or even just the solar pump) & then deduct that from the electricity the other meter records ? In my case (solar & gas) to prevent solar hot water over heat, in the summer I use the solar controller to start the heating circulation pump but not fire the boiler , thus the extra heat is dissipated through the boiler coils & bathroom rad.. I still yet to work out how this could work with a Heat pump. Looking forward to see how your cop improves with future modifications . These real life experiences on youtube are very good for building public (me) enthusiasm for the tech. Thanks.
Excellent. Better then I thought. Get the system temp to 35 and you should be laughing. How about the heating capacity? Were you able to maintain your thermostat temp on cold days ok? 19 20 21?
I’d also be inclined to keep the rads and see *if* they need to be bigger - I can imagine hundreds of useable rads being chucked purely because the calcs or fingers in air say so which seems daft to me. Insulation and draught proofing is a no-brainer but again can be done progressively if not already in place…
Here's a thought - perhaps your SCOP was bad in summer because you weren't generating heat for the house, just, presumably, hot water? That way you won't see a COP as such, especially if you have hot water heating all the time. I got that sorted quite quickly by setting hot water to heat for just one hour, 11-12 each night. With the general house heating set back, and probably being in bed, it doesn't matter if the heating is not on. The difference between hot water always being topped up, and the one hour a night regimen, is 60 or 70 kWh vs 12-15. Just think, and looking at your figures, if there is little going into the system in summer, there is nothing to register on the output side. Except hot water. Your January spike looks like my December 2022 spike, ongoing, as it has been close to zero C much of the time (that's NW Scotland for you) and ASHP's SCOP tends to crash somewhat, with the best settings in the world. Back in Sept/Oct/Nov my SCOP was an easy 2.5, and that was before I started tweaking settings eg. heat curve, max water temp in the CH loop, balancing the emitters (I got HUGE rads with my COMPLETELY FREE system, a fortunate moment in time when I qualified for a 100% grant, plus free wall cavity insulation! But things have been different here, north of the border). Yes, it is freakishly expensive to run at this time, freezing conditions here often, lecky at 32p a kWh. But before December it was much, much less. So I see the annual average coming out something similar to your own figures. That's me on my own, with health problems that dictate 23 C - honestly - needed in the daytime, with 21 C setback compromise (tbh, I have yet to experiment with no setback/a little setback/more setback and so on), although I can't stand a bedroom other than unheated! It's not a big house, but I am cosy all the time, and the coal and wood that fuelled my old wet heating system was costing £2,500 annually (!!!) and now I don't have to heft coal and wood in tonne loads 6 times a year... With the rise in coal and wood by well over 50% in my part of the world since last winter, I would reckon on £4,000 a year now! If I can heat my house just as well with the ASHP I now own, at half projected carbon fuel cost, I'm smiling all the way to the bank, as well as feeling a tad better about my carbon pollution. Given how much wind and hydro Scotland produces, I'm a happy bunny!
Hi Bob, whereabouts in Scotland are you? We've just bought a house in Ullapool and are looking at shifting from a multi-fuel stove with back boiler to ASHP just like you. There's a local company that fit Mitsubishi Ecodans, but I'm trying to research what the best option might be . What make do you have?
@@What10037 Oh yes, a Vaillant system, the model before the latest iteration. I imagine the grant models were the ones on offer to use up ‘old’ stock. Still, it’s a great improvement over solid fuel - coal will become almost impossible to get hold of soon, price is out of this world now as it is. And I am certainly paying rather less for electricity than I was previously for coal and wood. And without the hassle and back break, of shifting tons of the black stuff around every year!
You've kind of put the cart before the horse IMO. A home should really be 'heat pump ready', before sizing and selecting a unit. You should be achieving an average annual COP or SCOP of around 2.5 - 3. The more domestic hot water you use, the lower this figure, so maybe focus on your hot water usage and frequency of immersion top up. Thats probably why your summer COP is so poor.
You're totally right about putting the cart before the horse. Unfortunately we were influenced by the availability of a better grant. And the fear the that old oil boiler wouldn't make it until we'd sorted out the fabric of the house. Hopefully when we've sorted out the house (that work is now underway) the COP will improve. I'll be sure do another video for comparison when I've got another 12 months of data. Despite the mediocre performance, I'm still happier to have used a heat pump for the last year than if I'd stuck with oil.
I'll have to look at your other videos too. I am eying up replacements for my 24kw combi boiler as it's 8 years old but these heat pumps and a big tank do not look like they are any improvement at all! The fact you've ended up costing significantly more on electricity compared to oil is amazing(ly bad) as my mates that are on oil are all whining about the price of oil. It appears the more TH-cam vids I watch, the more I realise what I have, a small combi boiler in a small house is probably the most efficient, most cheap to buy, most low cost to run.
We're running with underfloor heating now. The efficiency and therefore running costs are much improved. I'll need to run it for a while longer to get good statistics but I strongly suspect that we're now cheaper than we would have been sticking with oil.
If you are not ready to upgrade your building envelope, you should have just left in the existing appliance. Or if it was available, put in a gas boiler.
We don't have gas available, so that was never an option. Ideally, we would have done exactly as you suggest, and installed the ASHP in after all the building upgrades. Two things got in the way of that plan though. Firstly, we took advantage of grants that existed at the time and saved ourselves £thousands in the process. Secondly, we had an old oil system. The boiler was still going (after about thirty years) but the oil storage tank was on the point of collapse and was listing dangerously. I didn't want to have to pay for a replacement tank that we would then get rid of again. So I guess it came down to money for both points!
I'm still baffled by air-to-water heat pumps. All that extra expense to put in new radiators or underfloor heating. Why not just put mini-split A/C units in? (Air-to-air heat pumps). You get air cooling in the summer, which ties in very well with solar production if you have solar panels. You get more responsive heat output in the winter, with ability to control each room built in. You get a better COP, as the air coming out the mini-split doesn't have to get up to more than about 25-30 degrees. It also means you can bin off all your rads, meaning less chance of water leakage in your house. The only thing you lose is the £5k grant, which is admittedly a lot of money. But the system overall may well be comparable, as the air to water systems seem to be eye wateringly expensive even with the £5k. Yes you have to heat your hot water. But this can be done cheaply overnight if you have a big tank and an immersion. You can even get heat pump water tanks now in the UK with the heat pump built into the tank. And again, with a solar diverter you get free hot water in the summer.
I believe cavities in external walls are there for a reason. Why is it being promoted that it is ok to fill them with insulation when doing this could bring damp problems further down the line?
I should have been clearer. The cavities in my house have board insulation fitted which only takes about half of the available space. Therefore there is still plenty of ventilation and no damp problems. Given the age of that part of the house (1970s approx) this is quite unusual and forward thinking.
Just for info if you have a COP of 2 the end production is 1W = 3W of work. You cannot lose/destroy energy only change it into another equal form of energy so 1W in + a COP of 2 is calculated as 1W in (converts to heat in the compressor/work) +2 COP = 3W of work (heat) out.
your wrong on a couple of things - first off your not running to hot, HT air pumps are typically set to 50c where gas/oil normally run 65. even in some properties turned to max of 85, 35c is typical for underfloor heating regardless of whether its heat pump or conventional , but normal rads need 45-50c. in this should have been clarified via your MCS qualified installer so everything from Rads recommended, pipe work, and further insulation; if you were going to underfloor heating a different low temp heat pump should have been recommended instead ., the fact that the window installers found about the installation that out instead of your MCS installer is very worrying. given that the calculations were created based on solid walls and double glazing and non isolating floors COP rating should have not been recommended if it fell below 3 the fact that even after finding out your property was more insulated and just getting a typical rating of 1.8 to 2,.2 would mean it is VERY expensive to run. and shouldn't have been recommended for the property at all. in regards to your summer COP rating being so poor I wonder if the installer has turned off Weather compensation in the menu this is normally done by unscruplus installers who often go back to a property after new oweners find its not getting as warm because of the weather compensation, so the rad feel like they are warming up than running luke warm. the fact that most of the time in summer your panels would be heating the hot water it shouldn't be consuming a fraction of what it should be for that time of the year. if any thing because of the seasonal difference in temp it should rise based on your numbers now we are looking at a typical 38-40p per kwh this is going to cost a significant more than your typical a rated gas system boiler, to the point where I would ask for a different MCS qualified installer to check the install, it really REALLY shouldn't be using this much based on the original Rating for example 3 years ago I moved into a new proptery After insulating my new (ish) property to 2023 new build levels, insulated both outside and inside external walls to r20 . and have a R32 insulation in the roof cavity and loft, this cost me around 10,000 to do, most of it done by myself, prior to upgrade we were using 30kwh a day after the upgrade and boiler swap from open vent to system A rated we were consuming just 5kwh equivent to heat. per day in peak winter some days thanks to the constant temp it only ran for an hour morning or night to supplement some days we had to open the window for fresh air to filter in where it was so warm, all the hot water from april to september thanks to weather compensation ment the boiler was turned off for months our bill came to a grand total of 420 for the year based on the NEW rate and 6.5 p for gas per KW . insulation is key we all know that but your Radiators should have been clearly told what should or shouldn't be upgraded, in general any single pane rad should go period. tripple rads really help a lot, but regardless of whether you have underfloor heating installed it shouldn't really mater as its the fabric that mattered on the energy rating graph on the consultancy., if anything you should be seeing a cop higher than 3 but your not. and underfloor only helps with radiating heat equally. they still only use 15mm pipe and micro bore pipes are 10mm (in most 1970 properties unless they had work done in the 80's where it swapped mainly to 22mm) yes they do drop the flow rate but again this should have been in the calculation whether its 15 or 10 mm the difference isn't huge a BTU in a rad is a BTU regardless and should have been in the calculation. its the water pump that governs circulation speed yes it will have to run faster on the small bore that the nature of small bore, but that should use the heat from the thermal store and heat exchanger not directly from the heat pump feed. i know your thinking green but really suggest you do your own calculations based on the new rates ASAP you may find adding a in line 15-20kwh may be all you need to supplement and may be even cheaper/greener if heated with bio fuel right now is 91p per litre typically. LPG is about the same. (so expect fewer BBQ running this year ) otherwise left as is you may be seeing bills well in excess of 3000 next winter, the cost of doing a significant upgrade in insulation . is still recommended but my experience of MCS installers has been poor to say the least 2 didn't do any true heat calculation there only recommendation was to swap the rad and increase the insulation, the final installer was honest to do a full assessment and because of this found that the BTU rating of the rads was more than sufficient but due to being listed prevented instulation to modern standards made it incomparable (or to quote the installer cost significanly more to run than conventinal) so we went with an LPG conversion
Thanks for the vid. I’ve had a Daikin Altherma 3H HT ASHP & Mixergy h/w cylinder since April 21 too. 220m2 2002 bungalow. We’ve had solar PV since 2012 with a Solic 200 electric diverter to heat h/w. I’ve doubled loft insulation to 300mm, triple glazed (we have a lot of windows), changed bathroom extractor fans to ones with covers. Even put covers over key holes to reduce drafts. We used just over 4000kWh in a year. With a SCOP of 3.67 using a Nest controller. I’ve changed to using Daikin weather compensation on the ASHP since April 22 to compare efficiency. My predicted electric usage was 7300kWh 😮 via the MCS estimates. My wife says home was warm enough. We matched oil boiler running costs to ASHP. Sorry forgot to say we didn’t change any radiators, have 12mm microbore drops to each radiator from 28 or 32mm mainline pipes in the loft. Check out my installation on Ecobubl TH-cam channel. I will watch you changes with interest. I’ve been gradually turning down the ASHP flow temp. And weather compensation will impact this more, but run my external unit more. Thanks again
Thank you so much for putting the stats out. Very helpful. I have heard the more the heat pump starts and stops then lower the cop. Looking forward to see more.
This is a far better comparison for people interested in an ASHP as it a direct comparison for 2 different souces of heat. The mitigation being that it can be improved by under floor heating. There are too many people on youtube showing heat pumps working well with a std home heating systems (radiators) and they just dont.
I would guess your summer COP is low because it always will be when producing only hot water (60C+) the compressor is working at its hardest. But its true for all consumers and therefore a fair statistic to note.
Thanks for your comments. We've got the underfloor heating now. When it's been running for a few months I'll do an update for comparison.
How did you chose your flow temp? Did you run low and creep it up if you were cold? The design temp is usually for -2 in the UK. So for spring and autumn you should be able to run much lower. Maybe play with your weather compensation curve. We have a radiator and ufh mix with part insulated terrace house and get a cop of 4 or even 5 during warm ish oct and Sept.
Solar thermal appears to to give lower cop figure... Sounds plausible , If you have a heat meter on the heap pump flow & return pipes. The solar could give you all the hot water & the heat meter record nothing & record a COP of 0!). Should be possible to put a simple energy meter on the solar thermal controller ( or even just the solar pump) & then deduct that from the electricity the other meter records ?
In my case (solar & gas) to prevent solar hot water over heat, in the summer I use the solar controller to start the heating circulation pump but not fire the boiler , thus the extra heat is dissipated through the boiler coils & bathroom rad.. I still yet to work out how this could work with a Heat pump.
Looking forward to see how your cop improves with future modifications . These real life experiences on youtube are very good for building public (me) enthusiasm for the tech. Thanks.
Excellent. Better then I thought. Get the system temp to 35 and you should be laughing. How about the heating capacity? Were you able to maintain your thermostat temp on cold days ok? 19 20 21?
I’d also be inclined to keep the rads and see *if* they need to be bigger - I can imagine hundreds of useable rads being chucked purely because the calcs or fingers in air say so which seems daft to me. Insulation and draught proofing is a no-brainer but again can be done progressively if not already in place…
Have you seen Michael de Podesta's TH-cam vid concerning ASHP power.
Here's a thought - perhaps your SCOP was bad in summer because you weren't generating heat for the house, just, presumably, hot water? That way you won't see a COP as such, especially if you have hot water heating all the time. I got that sorted quite quickly by setting hot water to heat for just one hour, 11-12 each night. With the general house heating set back, and probably being in bed, it doesn't matter if the heating is not on. The difference between hot water always being topped up, and the one hour a night regimen, is 60 or 70 kWh vs 12-15. Just think, and looking at your figures, if there is little going into the system in summer, there is nothing to register on the output side. Except hot water. Your January spike looks like my December 2022 spike, ongoing, as it has been close to zero C much of the time (that's NW Scotland for you) and ASHP's SCOP tends to crash somewhat, with the best settings in the world. Back in Sept/Oct/Nov my SCOP was an easy 2.5, and that was before I started tweaking settings eg. heat curve, max water temp in the CH loop, balancing the emitters (I got HUGE rads with my COMPLETELY FREE system, a fortunate moment in time when I qualified for a 100% grant, plus free wall cavity insulation! But things have been different here, north of the border). Yes, it is freakishly expensive to run at this time, freezing conditions here often, lecky at 32p a kWh. But before December it was much, much less. So I see the annual average coming out something similar to your own figures. That's me on my own, with health problems that dictate 23 C - honestly - needed in the daytime, with 21 C setback compromise (tbh, I have yet to experiment with no setback/a little setback/more setback and so on), although I can't stand a bedroom other than unheated! It's not a big house, but I am cosy all the time, and the coal and wood that fuelled my old wet heating system was costing £2,500 annually (!!!) and now I don't have to heft coal and wood in tonne loads 6 times a year... With the rise in coal and wood by well over 50% in my part of the world since last winter, I would reckon on £4,000 a year now! If I can heat my house just as well with the ASHP I now own, at half projected carbon fuel cost, I'm smiling all the way to the bank, as well as feeling a tad better about my carbon pollution. Given how much wind and hydro Scotland produces, I'm a happy bunny!
Hi Bob, whereabouts in Scotland are you? We've just bought a house in Ullapool and are looking at shifting from a multi-fuel stove with back boiler to ASHP just like you. There's a local company that fit Mitsubishi Ecodans, but I'm trying to research what the best option might be . What make do you have?
@@What10037 Oh yes, a Vaillant system, the model before the latest iteration. I imagine the grant models were the ones on offer to use up ‘old’ stock. Still, it’s a great improvement over solid fuel - coal will become almost impossible to get hold of soon, price is out of this world now as it is. And I am certainly paying rather less for electricity than I was previously for coal and wood. And without the hassle and back break, of shifting tons of the black stuff around every year!
You've kind of put the cart before the horse IMO. A home should really be 'heat pump ready', before sizing and selecting a unit. You should be achieving an average annual COP or SCOP of around 2.5 - 3. The more domestic hot water you use, the lower this figure, so maybe focus on your hot water usage and frequency of immersion top up. Thats probably why your summer COP is so poor.
You're totally right about putting the cart before the horse. Unfortunately we were influenced by the availability of a better grant. And the fear the that old oil boiler wouldn't make it until we'd sorted out the fabric of the house. Hopefully when we've sorted out the house (that work is now underway) the COP will improve. I'll be sure do another video for comparison when I've got another 12 months of data. Despite the mediocre performance, I'm still happier to have used a heat pump for the last year than if I'd stuck with oil.
I'll have to look at your other videos too. I am eying up replacements for my 24kw combi boiler as it's 8 years old but these heat pumps and a big tank do not look like they are any improvement at all! The fact you've ended up costing significantly more on electricity compared to oil is amazing(ly bad) as my mates that are on oil are all whining about the price of oil. It appears the more TH-cam vids I watch, the more I realise what I have, a small combi boiler in a small house is probably the most efficient, most cheap to buy, most low cost to run.
We're running with underfloor heating now. The efficiency and therefore running costs are much improved. I'll need to run it for a while longer to get good statistics but I strongly suspect that we're now cheaper than we would have been sticking with oil.
I think the cop doesn't get to optimal values due to the system not running for a longer time window.
If you are not ready to upgrade your building envelope, you should have just left in the existing appliance. Or if it was available, put in a gas boiler.
We don't have gas available, so that was never an option. Ideally, we would have done exactly as you suggest, and installed the ASHP in after all the building upgrades. Two things got in the way of that plan though. Firstly, we took advantage of grants that existed at the time and saved ourselves £thousands in the process. Secondly, we had an old oil system. The boiler was still going (after about thirty years) but the oil storage tank was on the point of collapse and was listing dangerously. I didn't want to have to pay for a replacement tank that we would then get rid of again. So I guess it came down to money for both points!
@@GreenTubers I guess that’s the reality of it all, gotta spend the green bucks to go green.
Fabric first. A better approach is to use that 12300£ into insulation, air tightness, mhvr so you don’t need a heat pump for space heating.
We have also spent money on other factors, we just did it in the wrong order (due to the availability of a grant).
I'm still baffled by air-to-water heat pumps. All that extra expense to put in new radiators or underfloor heating.
Why not just put mini-split A/C units in? (Air-to-air heat pumps).
You get air cooling in the summer, which ties in very well with solar production if you have solar panels.
You get more responsive heat output in the winter, with ability to control each room built in.
You get a better COP, as the air coming out the mini-split doesn't have to get up to more than about 25-30 degrees.
It also means you can bin off all your rads, meaning less chance of water leakage in your house.
The only thing you lose is the £5k grant, which is admittedly a lot of money. But the system overall may well be comparable, as the air to water systems seem to be eye wateringly expensive even with the £5k.
Yes you have to heat your hot water. But this can be done cheaply overnight if you have a big tank and an immersion. You can even get heat pump water tanks now in the UK with the heat pump built into the tank. And again, with a solar diverter you get free hot water in the summer.
I believe cavities in external walls are there for a reason. Why is it being promoted that it is ok to fill them with insulation when doing this could bring damp problems further down the line?
I should have been clearer. The cavities in my house have board insulation fitted which only takes about half of the available space. Therefore there is still plenty of ventilation and no damp problems. Given the age of that part of the house (1970s approx) this is quite unusual and forward thinking.
Just for info if you have a COP of 2 the end production is 1W = 3W of work. You cannot lose/destroy energy only change it into another equal form of energy so 1W in + a COP of 2 is calculated as 1W in (converts to heat in the compressor/work) +2 COP = 3W of work (heat) out.
your wrong on a couple of things - first off your not running to hot, HT air pumps are typically set to 50c where gas/oil normally run 65. even in some properties turned to max of 85, 35c is typical for underfloor heating regardless of whether its heat pump or conventional , but normal rads need 45-50c. in this should have been clarified via your MCS qualified installer so everything from Rads recommended, pipe work, and further insulation; if you were going to underfloor heating a different low temp heat pump should have been recommended instead ., the fact that the window installers found about the installation that out instead of your MCS installer is very worrying.
given that the calculations were created based on solid walls and double glazing and non isolating floors COP rating should have not been recommended if it fell below 3 the fact that even after finding out your property was more insulated and just getting a typical rating of 1.8 to 2,.2 would mean it is VERY expensive to run. and shouldn't have been recommended for the property at all.
in regards to your summer COP rating being so poor I wonder if the installer has turned off Weather compensation in the menu this is normally done by unscruplus installers who often go back to a property after new oweners find its not getting as warm because of the weather compensation, so the rad feel like they are warming up than running luke warm. the fact that most of the time in summer your panels would be heating the hot water it shouldn't be consuming a fraction of what it should be for that time of the year. if any thing because of the seasonal difference in temp it should rise based on your numbers now we are looking at a typical 38-40p per kwh this is going to cost a significant more than your typical a rated gas system boiler, to the point where I would ask for a different MCS qualified installer to check the install, it really REALLY shouldn't be using this much based on the original Rating
for example 3 years ago I moved into a new proptery After insulating my new (ish) property to 2023 new build levels, insulated both outside and inside external walls to r20 . and have a R32 insulation in the roof cavity and loft, this cost me around 10,000 to do, most of it done by myself, prior to upgrade we were using 30kwh a day
after the upgrade and boiler swap from open vent to system A rated we were consuming just 5kwh equivent to heat. per day in peak winter some days thanks to the constant temp it only ran for an hour morning or night to supplement some days we had to open the window for fresh air to filter in where it was so warm, all the hot water from april to september thanks to weather compensation ment the boiler was turned off for months our bill came to a grand total of 420 for the year based on the NEW rate and 6.5 p for gas per KW .
insulation is key we all know that but your Radiators should have been clearly told what should or shouldn't be upgraded, in general any single pane rad should go period. tripple rads really help a lot, but regardless of whether you have underfloor heating installed it shouldn't really mater as its the fabric that mattered on the energy rating graph on the consultancy., if anything you should be seeing a cop higher than 3 but your not. and underfloor only helps with radiating heat equally. they still only use 15mm pipe and micro bore pipes are 10mm (in most 1970 properties unless they had work done in the 80's where it swapped mainly to 22mm) yes they do drop the flow rate but again this should have been in the calculation whether its 15 or 10 mm the difference isn't huge a BTU in a rad is a BTU regardless and should have been in the calculation. its the water pump that governs circulation speed yes it will have to run faster on the small bore that the nature of small bore, but that should use the heat from the thermal store and heat exchanger not directly from the heat pump feed.
i know your thinking green but really suggest you do your own calculations based on the new rates ASAP you may find adding a in line 15-20kwh may be all you need to supplement and may be even cheaper/greener if heated with bio fuel right now is 91p per litre typically. LPG is about the same. (so expect fewer BBQ running this year ) otherwise left as is you may be seeing bills well in excess of 3000 next winter,
the cost of doing a significant upgrade in insulation . is still recommended but my experience of MCS installers has been poor to say the least 2 didn't do any true heat calculation there only recommendation was to swap the rad and increase the insulation, the final installer was honest to do a full assessment and because of this found that the BTU rating of the rads was more than sufficient but due to being listed prevented instulation to modern standards made it incomparable (or to quote the installer cost significanly more to run than conventinal) so we went with an LPG conversion
Interesting 🤓
hate the way people woffle-on on youtube videos..
Me too