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My brother lives in Norway the temp went down to -40 this year his main heat source is a heat pump Your right on insulation but wrong about heat pumps if the Norwegians can do it it should be a piece of cake for us

Heatpumps are the most common means of heating in Norway. They are ‘less’ efficient, true. But they aren’t inefficient. But as for poorly insulated homes, the heatgeek channel as a few examples that show heatpumps work well in old buildings. Of course you should bump up the insulation where it’s possible. Loft insulation and draught proofing are easy wins, and dehumidifiers also help if damp is a concern.

@@anthonydyer3939 it depends on type. Many homes in Scandinavia use ground source, or internal air recirc HPs. But pure external ASHPs are very inefficient below freezing as they need to defrost. Their construction standards are much higher than UK more like ‘passiv haus’ with timber frame and wood burners used to supplement. HPs can heat the HW demand in cold climates but space heating needs good insulation built in by design and their energy costs are much lower compared to UK

I removed all the Thermostatic valve regulators for the radiators since this video. They were giving me “trust issues”. They were wound up to their maximum end stops, and the advice received three times from both plumber and heatpump engineer was to make sure the radiator valves were all maxed out. So I wandered “what if the valves are closing in anyway?”. So the answer was that they weren’t. The DeltaT was exhibiting the same behaviour. The minimum compressor current is the culprit. Most times it’s 1.3 Amps, but it’s only when it drops to 0.5Amps that I see much better COP. I’ve pored over the data to ask the question of what the system or environmental difference is between a 0.5Amp or 1.3 Amp situation. I can’t find the answer. Sometimes I’ve seen stubborn minimums at 1.8 and 2.3 Amps with similar outcomes for COP. Right now I’d need Daikins source code to find that answer, and I don’t have the contacts or reverse engineering know how to extract that data. As the weather has gotten warmer, I’ve seen other weird behaviour. When inside temp is 24 degrees or higher, the hot water heating mode refuses to engage until I reboot the heatpump. Once the inside temperature drops below 23 degrees (the absolute cutoff for any space heating operation), the hot water cycle will engage correctly. I do feel like this could be fixed with a software update, and one firmware update was offering, update download failed, and the update was then withdrawn.

If we take the Eviny (and Circle K) chargers for example: I tried registering my account when I was back home. The registration attempt still failed. Those chargers are available exclusively only to Scandinavian telephone numbers.

It’s not common, but Clancool have used these frames on other projects. They gave me the choice of the standard feet, or the elevated frame. I have had 40cm snow back in 2010, so it was an easy choice to make.

That statement sounds very romantic, but actually an Englishman's castle is subject to building regulations (sometimes retrospective) and plenty of other laws. ..... and it's taxed (Stamp Duty, Council Tax, Capital Gains on 2nd homes, VAT on new homes) .... and some authorities have rights of entry into your home under certain circumstances. When you consider all that, it's not that different to a Scotman's home, is it?

Yes we have the leasehold free variety up here in Grampian (castle country), and the council tax freeze this year, what a struggle sometimes :-)

The normalisation of insulation is part of the point of that bill with the stipulation of minimum energy standards by 2033. But in the consultation, they make the very valid point that no matter how good your insulation is, if your heating source is still emitting CO2, then while you reduce your CO2 emissions, you cannot eliminate them. Hence the need to ban gas boilers. But your point on reserved energy policy is a good one. Politics is, quite messy. Seemingly an art, rather than a science.

@@anthonydyer3939 There is method in it -O&G will fight it tooth and claw, so likely the drop-dead will be extended, but insulation levels will become mandatory as trade-off - Does the politics of it make sense now ? ;) You saw the nonsense in Scotland's media over heatpumps when they went after the Greens, that was just the rehearsal....

@@anthonydyer3939 I meant to clarify I was referring to existing homes with regards energy efficiency - It will be many years before existing gas and oil boilers begin becoming obsolete, and with HMG's history of blocking retro-insulation at public cost, SG have to a find a workaround if they are to reduce emissions and release more energy on the grid - As I've exampled with a relatively modern house, 80% reduction in heating consumption is possible, in my own case hydrocarbon, but it equally applies to electricity - It is easier politically for SG to establish legislation for new build, then extend it later to improve existing property if you follow... PS - I've got about 15 of the DS18B20 temp sensors crimped into phone jacks to all spaces in/out on a single run of Cat5E from an Arduino radio node - Now in it's 7th year of faithful operation, with one change of 2xAA backup batteries.... The lower frequency penetrates concrete and masonry walls with ease...

@@robertlamont9455 About 1.5 Million gas boilers are replaced each year in UK, surely a prime target for heat pump replacements ?

@@_Dougaldog With ca 30M households heated by various means in the UK, that figure doesn't make sense. I'm not against heat-pumps, far from it - It's the 'gas boilers are bad' and lost perspective on reducing heat-loss I find disconcerting - For new build the issue doesn't arise, but for the bulk of the UK's older housing stock there's a danger it is not fully addressed and the 25% saving in running costs becomes the carrot in switching to electrical power on an already stuggling grid. eg - The 80% gas reduction on my 2013 new build cost 1k in insulation etc., so should be achievable cheaply on older UK properties, and this is the main point, IRRESPECTIVE OF HEAT SOURCE - That's the point we should be hammering home to the public, 80% off their bills now and taking the strain off the grid for the rise in EVs and HPs etc into the future... - Heat pump uptake will be limited by manufacturing production capacity in any instance...

In theory, yes. But as one estate agent said: Two properties side by side seemingly identical, except one needs something fixed. The price difference between the properties may not match the cost of works needed to put it right. A sellers market the price difference could well be zero. In a buyers market the price difference could be very wide.

I remember in Denmark when it was snowing and well below zero, you could see where the pipes were running underneath the roads. I would have thought the earth would have been a good insulator, but evidently not enough! The whole lot was waste heat conveyed from their local gas power stations. It’s a very efficient and joined up way to get as much useful energy out of your plant.

​@@anthonydyer3939most didn't use gas. Many used waste heat sold by factories, waste to heat incinerators, even local power plants who would have dumped the heat otherwise

Agreed. I was astonished to see that over 40% of commercial properties were G rated on their EPC’s. But then, I’ve got a feeling a lot of these properties are vacant and probably in a poor state of repair. I have a feeling that many commercial landlords if push comes to shove will simply say “not worth it - time to demolish”. We’ve also got the RAAC concrete debacle going on, and the unsellable flats due to the flammable cladding. Between them, that’s a lot of property ripe for demolition anyway. I can only hope the replacement buildings are better.

I looked into PassivHaus and EnerPhit. PassivHaus is definitely something that should be built into all new builds. But as a retrofit project it’s very costly and disruptive, especially when it comes to junctions between wall and floor. For my house - concrete wall cladding would have to be deleted and replaced with an exterior rockwool/ backer board solution. The eaves space would require insulation to delete a cold bridge. All the windows and doors would require replacement. Project costs are probably £75k for my house. Why do that when Heatpump + battery + solar can, in gross terms, supply all my energy needs over the course of a year for £36k?

@@anthonydyer3939 yes, no an easy solution for some existing properties. That said, once fitted it should be therefor the life of the building, with few running costs.

I've been looking at the alternatives for my house, and a heat pump is massively cheaper than improving the insulation. Exterior (or interior) wall insulation would be about £30k, triple glazing would be £20-30k, and I didn't even start looking at the cost of ripping out a solid concrete floor. By comparison, £10-15k for a heat pump looks like a bargain!

It’s cotton, my girlfriend designed it. It’s ‘One of a kind’.

The worst consequences of a bad install do not involve a gas explosion. There’s 1.8kg of R32 in my system. It’s very hard to ignite. You need a concentration in air of at least 300g/m3 to get ignition. The consequence of ignition is a slow moving flame front. arema.com.au/wp-content/uploads/2021/11/R32-FACT-SHEET.pdf In other words leaks outside, in a crawl space or a room will not result in high enough concentrations. A “full bore” leaks in a cupboard could result in high concentration, but sparks from electrical switching don’t have enough energy to cause ignition. Therefore if the worst consequences are no worse that typical DIY work then it’s not going to catch the headlines in the same way. Many DIYers are no stranger to crawl spaces and loft access. But certainly work at heights on the outside wall of a flat (with no balcony) is a professional job. I wouldn’t want a compressor to fall on my head! Training up gas engineers certainly needs to happen, but DIY installs are the consequence when that doesn’t happen.

@@anthonydyer3939 I thought all the new systems used propane. The DIY air to air, the pipes normally go straight from outside, through the wall to the back of the interior unit, so no significant risk? I assume there is an alarm built in, and propane can have a strong smell added. That said it is heavier than air, so can collect at low points, hence very dangerous in boats.

@@markthomasson5077 R32 is very common: That’s Di-floro-methane. It’s only ‘mildly flammable’, but you need to be F-Gas registered to handle it. Then there’s R290: that’s Propane. So Propane is the ‘new kid on the block’. Much more flammable, but it has excellent refrigerant properties, including higher temperature performance. Typically it’s offered only as a monobloc product. So you’re not running pipework for propane as it’s all self contained in the heatpump. Thus you don’t need special qualifications to handle such heatpumps. I was actually very surprised to see that product I flashed up as being an R290 refrigerant. Because that unit was a split refrigerant unit. That’s tricky: Now when it comes to Propane, the Gas Safe Register qualification is only good up to a certain pressure. Refrigerants are compressed up to 30-60bar, far beyond the limits written down in your qualification. So I’m not too sure where a split R290 product sits in terms of qualification requirements.

Governments love complexity. I think yes minister and yes prime minister illustrated the point succinctly many times. Why buy stationary at WHSmith and put it on expenses when you can do it for 10 times the cost through a convoluted requisition process? I’m sure similar processes were observed during Roman times. …and so it was when claiming the grant for a heatpump. All told I think air to air solutions are the long term winner here. They’re simply cheaper, and as I illustrated briefly, the hardware doesn’t have to be expensive at all. Once the solutions are cheap, the grants with all their in built admin costs become obsolete.

@@anthonydyer3939 probably already the case for me, I am single, use an electric shower, and under sink unit in the kitchen. So Air to air still may still sense even without the grant.

I don’t think new builds qualify for subsidies. But these systems are scalable to all housing types. I’m always dismayed at how old fashioned methods are when it comes to construction of homes and buildings. I’ve been to Korean Shipyards, and they made “Lego blocks” of the different sections of a ship straight off an Autocad drawing into an automated steel cutter, and then the Lego blocks are fabricated in a factory environment. Human welders are only needed to put the Lego blocks together to make up the ship. Compare that to construction sites. Much traditional joinery is still done on site, same with plumbing and electrics. It could all be done in a factory in controlled conditions and shipped out as a module bolted to other modules on site. It would save a lot of cost and improve quality. Then we’d have a chance at truly affordable housing. Sadly the construction industry is extremely conservative and reluctant to change.

I upgraded a 1935 house to double insulation and underfloor heating on the groundfloor, I use around 80% less energy to heat the building, my brother lives in Norway they have a small heatpump which provides blown air, the house is super insulated though.

So you could just leave it to market forces. But, as usual, the SNP has to virtue signal. God forbid they should do anything about the terrible state of Scottish education or health!

@@edwardkenworthy7013 Caring about the environment is not limited to one political party or government. Only the UK domestic market seems to lag the rest of the world in adoption of heat pumps. The Scottish education and health systems have served me well.

I can certainly tell you that Aberdeen Airport is very quiet these days 3.7million passengers in 2014 vs 2 million in 2023. Outside covid, it’s the lowest count. It’s even lower than it was during the oil price crash from 2015 to 2017. By all accounts North Sea oil production volumes are still trending ever lower, and the number of exploration/development wells is following that same trend: app.powerbi.com/view?r=eyJrIjoiNjkzYjNmMWUtMWY2MS00OGY4LThmYWItN2UxMDM5NmRjODIyIiwidCI6ImU2ODFjNTlkLTg2OGUtNDg4Ny04MGZhLWNlMzZmMWYyMWIwZiJ9 So it’s fair to say that my region needs to come to terms with that and embrace new opportunities.

Albert Einstein - 'The only difference between genius and insanity is that genius has its limits.' Unintended consequences: Energy Performance becomes a hot housing market commodity. Poorly insulated houses not worth upgrading and not worth buying, and therefore they become abandoned. Resulting housing shortage either results in steady depopulation through emigration and low birth rates - or a construction boom with the old houses demolished and new houses to replace them. To be quite plain, we’ve had a housing crisis for about 20 years now. The recent aerated concrete scandal has now infected social housing and that’s leading to a rather sudden abandonment of properties. Indeed after the 2nd world war, we had a housing crisis back then. The solutions aren’t always good: Ugly high rise builds are too often crime infested and fall into disrepair. Nonetheless, every time there’s a crisis, there’s also employment opportunity. Just so long as there’s money to do it. That’s a big if, now back to Einstein’s quote.

It’s one of the tragedies of climate change. The proposals to change things are simultaneously too ambitious and not ambitious enough! Too ambitious: People can’t afford the change’s by themselves, and government can’t afford the grants they offer to us Not ambitious enough: The climate is still heading for significant warming

@@anthonydyer3939 I think most people see being comfortable more important than saving the environment. And that reflects into what politics do. I only heat one room, living room is 13...16 degrees in the winter and therefore my carbon footprint is low. Not many people want to live that way.

There is a much larger overall demand on the grid with 100% adoption of both heatpumps and EVs There was a discussion about the power grid being able to manage an overnight switch of everyone switching from ICE to EV. We actually have lots of spare capacity at night time. Then you’ve got rooftop solar. It achieves a lot to mitigate grid demand and it’s a perfect seasonal neighbour to wind power. Heatpumps are a different beast, since they need to run at a constant rate and demand will be highest on the coldest of nights. To that I say we’ve got 20 years of steadily rising grid demand for the transmission and distribution companies to match that with additional supply. This is not a problem that happens suddenly overnight. But heatpumps are quite versatile. The high temperature models are a better fit for older heating systems (but not as efficient as low temperature models). They have been demonstrated to work well in a Victorian house.

​@@anthonydyer3939 not sure what you mean by "need to run at a constant rate"...Heat pumps, if commissioned properly with weather compensation, will only draw a heavy load in the coldest of temperatures; when it is not cold they barely draw anything noteworthy.

@@michaelwinkley2302 That’s my point. They don’t run at 100% for short periods and then remain off for long periods. It’s not like a thermostatically controlled boiled. My heatpump is quite happy with a continuous 350W load when it’s 7 degrees outside. If you start switching it on/off at different times of the day then you aren’t getting the best performance out of it.

You’re right that they don’t know what they’re missing out on, but it’s human nature to be wary of big change when big costs are involved. Building trust is a fragile thing: Phenomenally hard work, easily eroded by malicious actors. And yet, you know that maintaining the status quo is even worse in the long run. I keep reminding people of how bad 2022 was: It can happen again, gas cannot be relied upon anymore.

I read too many tales from real people about buying an EV so I bought another PHEV. We're in our 70s and in the near future may need to move house. We have to consider not being able to charge at home. EVs aren't very economical at 79p per KWh. My daughter cannot charge at home. Nor can they afford a decent EV

@@allan4787 The roadside prices are outrageous right now, and it does nothing to encourage adoption of EVs. As you say, not everyone has charging capability at home. At this stage with EVs, only lower EV and electricity prices are going to help with EV sales. Aside from that, streetside charging outside your house at the same price as what you pay for electricity in your house - that needs to happen. I’m hopeful about the former, but not about the latter.

@@allan4787 I believe Tesla have now opened up their chargers to all, and a monthly fee (round about £9) gives full access to Tesla fast chargers, and their off peak rate of 20p/kWh. I am considering this as a future option, as I'm not in a position to charge at home.

@@anthonydyer3939 I bought my first PHEV in 2015 believe it or not for some time after that some public chargers were free. I need to install a type 2 , I have had a type 1 since 2015, it was free to me. The type 2 doesn't have an incentive and commands VAT!!!!

It’s certainly a big commitment, and the test of your statement is whether the savings in your energy bills as a result of your investment exceed or fail to cover the repayment costs for any loan that you take out. That’s the only reasoned difference to separate public support from open hostility. The green deal schemes unravelled exactly like this and they were abandoned by the uk government. That is not a good foundation for trust in this proposed law. I’m personally wary of community heat networks. They are run by companies (no doubt for profit) with a monopoly over your heating. There’s a lot of underground works (digging up streets and pavements) needed to install the network, so capital costs will be high. I wouldn’t be too surprised if you’re contractually committed to an indefinite standing charge with no exit option at which point they can charge silly money for heating.

@@anthonydyer3939 Yes, good points. I think the energy supply has to be diverse realistic and fair. For us, solar works great but that doesn't mean it's a good fit for someone living in a Victorian terrace with no garage.

I’ve just been having a look at this page, and I can’t see any upper age limit restrictions mentioned. www.homeenergyscotland.org/funding/grants-loans/detail/ Does the age restriction also apply to grants?

@@anthonydyer3939 I honestly don't know, it may do. As I say I don't need a loan or a grant. I'm staying on gas until it's no longer the cheapest. I'm really not sure who I was talking to, it was all over the phone, but they suddenly went quiet when I gave them my DOB .

@@allan4787 It’s likely you didn’t call Home Energy Scotland, but somebody else. I will say that if you’re on mains gas, heatpumps are a hard sell right now. For you, my best opinion is to stick with gas.

@@anthonydyer3939 You're very likely correct. re:- gas yes . We have an impossible to insulate house. 1890 sandstone building slate roof,

@@allan4787 "but they suddenly went quiet when I gave them my DOB" Could they have been 'phishing' for personal data ? 🤔

I saw the Skill Builder Heat Geek collaboration with that LG heatpump making a terrible whine. It was very interesting how critical a level base is to quietness and long term wear on fan bearings.

@@anthonydyer3939 makes me nervous about getting one and if my neighbours get one.

@@Mark-M72 There’s a lot of good advice on the heatgeek channel. They give you a load of questions that you should ask any prospective installers. The answers to those questions sort the sales driven companies from the the more technically oriented companies. Also: Heatgeek approved companies are now guaranteeing the SCOP that they provided in your quote. That essentially give you an assured indication of the running costs for your heatpump. I haven’t got one of those guarantees, but I think it’s a really good initiative.

​@@anthonydyer3939 Gravity pulls vertically down. If you don't mount motors level it puts tangential loads on the bearings and causes all sorts of problem's. Noise, premature wear, seal failures.

​@@Mark-M72 As Anthony mentioned, if you walk around a big city in Southern Europe, you will see split unit ACs all over the place, often dozens for a single apartment block as most units are single splits, meaning they heat/cool a single room. The noise is really not an issue, you might here the odd whine from an old unit on its last legs but mostly just the whirring of a fan. No more noise, if anything less, than you'd hear from a gas boiler exhaust.

In any market, prices are dictated by “the supplier of last resort”, but it assumes that supplier is actually in demand. In not, then it’s dictated by the 2nd to last resort supplier and so on. Good news is that 0% fossil fuel grid is forecast to be upon us next year (for a least a few seconds). www.carbonbrief.org/analysis-fossil-fuels-fall-to-record-low-2-4-of-british-electricity/ By 2035, the uk grid will be a very different beast. In the meantime prices are lower this year, and that’s worth some relief, even though it’s still much higher than prepandemic prices. Next year…. We’ll see what happens as usual.

That's because the country next door stopped installing onshore wind in 2015, so they still use gas, and that sets our price.

CO2 in the atmosphere= 0.04%. Human contribution is 3% of this = 0.001%. The Western world... US, Canada, Europe and Australasia contributes 28% of that 0.001%= 0.00028% of the CO2 in the atmosphere. I hope people come to their senses soon and scrap all of this climate is the result of CO2 nonsense. In my case gas is by far the most economic way of heating my 1890 solid stone built house

@@allan4787 Your 0.04% was just over 0.02% prior to the UK lead industrial revolution. An almost 100% increase, that's the problem.

@@_Dougaldog And volcanic activity??

UK might struggle for food later this year as torrential rain has wiped out crops and increase in imports from Europe as new checks on all incoming goods come into play, with England seeing wettest 18 month period since records began in 1836. Same checks on fresh fruit and veg to follow later in the year, a WTO requirement. However Civil War is highly unlikely.

The simplest solution is to have a wall mounted heatpump on the tenement flat outside, and multisplit emitters inside the property. They do this with AC units on flats everywhere else in the world. But here - you need planning permission, and permission from the building owner. They both might say ‘no’. It’s a shame, because it really isn’t rocket science to install these things.

Network heat will most likely fail, unless its very cheap to run. Lots of underground works needed, and I remember when my childhood village was dug up to introduce gas in the early 1990’s. It was very disruptive, but ultimately it was very popular given the price of gas at the time.

Near my house: 5 heatpump MCS registrations vs over 80 gas safe registered engineers. You’re right there aren’t enough qualified people. Two things though: 1. Rising demand for heatpumps will encourage more installers to train up 2. Newer R290 designs bypass the F-Gas regulations entirely, so it’s easier to train up installers. 3. Sooner or later I think the government has to go in the direction of the USA and allow DIY installs of air conditioning. Yes there’s a higher risk of escaping gas to atmosphere, but the risk is small compared to the certainty of continued CO2 emissions. By far the biggest challenge is overcoming cultural inertia. People stick with what they know works. It’s hard to get people to break with that comforting sense of familiarity.

@@anthonydyer3939 . Yep, been watching quite a few YT vids of people having air2air installed- it seems pretty simple yet they are often paying way over £2K for the install. Heat pump water cylinders also seem excessively expensive.

@@bordersw1239 if I was to get my project done cheap I would have left the old hot water cylinder in situ. During the hot water heating cycle it takes 30 minutes to heat up the hot water. Out of that time it takes about 10 minutes just to warmup the heating loop up to the same temperature as the hot water tank. It’s very perplexing why it takes such a long time but once the hot water tank setpoint temperature is reached the circulation pump switches off instantly and the means that the energy remaining in the heating loops is wasted rather than being transferred into your water tank. A simple defect to fix in software: keep circulation pump running until leaving water temperature < tank temperature. The tank would warm up a bit more and you’d save that energy. If I knew that before getting the heatpump hot water cylinder, I would have just simply stuck with excess solar water resistive heating as a means of heating up the hot water. The amount of energy I spend heating up hot water is quite small for my household compared to heating the house so the benefit is well into diminishing returns territory.

Anecdotally have heard of more people ripping out heat pumps than installing them. Some really bad installations out there. Currently with oil, but it's 90+% efficient so it's not as obvious a change as going for an electric car (which I did years ago). I am tempted by air to air mini splits and sunamp for hot water (make the most of my cheap overnight electricity). Can install that while keeping the combi boiler and see how it runs as a hybrid system, it's a fraction of the cost of a heat pump, but there's no subsidies whatsoever for air to air. Think the biomass needs to be left alone, at least as backup heating. Know lots of people who had no power for a fortnight after Storm Arwen. Norway stipulates a backup form of heating is required. Easy way to get people to install electric heating, drop the price of electricity.

@@grahamleiper1538I’m going to have to say, if I was on a standard variable rate, I would not have invested in heatpumps. There was only very marginal savings in running cost. It’s only by virtue of my renewable investments + Intelligent Go that this solution is worthwhile. I think it’s fair to suggest most households won’t be switched onto that opportunity until Solar + batteries become cheaper than roof tiles and fancy iPhones. I think five more years will do it.

The inverter is connected using Ethernet. But there’s no trouble connecting my laptop to the inverter via wifi to the router. The wifi modbus restriction only applies if the inverter is connected to the router via wifi. It has no idea how the origin of the modbus master is connected.

That’s how that mode works, and therefore it needs selective use. I only use it from 10am to 3pm and only during bright spring summer days. Outside that time I use “discharge to minimise import” during the morning, and “max self consumption” after 3pm to pick up any remaining charge for the battery What I’m going to try is using modbus to select between this mode and “discharge to minimise import”, depending on power consumption in the house and maybe the weather forecast. I dont use “discharge to maximise export” during the evening anymore since I’m not on Octopus Flux.

Okay, I misunderstood that mode then… I’ll look into the discharge to minimise import option and see how I can make it work for me Thanks for the reply 👍🏼

Wouldn't compressor failure protection be dictated by refrigerant parameters rather central heating water parameters? We have refrigerant discharge pressure/temperatures for example, and those are under PID control. Your target discharge temperature for example was continuing to rise up. Current draw was only 9 amps at the top end of that heating session - well within the 14 amp maximum.

Since this video, I’m definitely placing a lot more focus on the DeltaT. It’s about 3-4 degrees when COP is high, but only 1-2 degrees when COP is low. It’s definitely the case, when the house is cold (e.g. turning on when returning from holiday) the COP is very high. But when the house is 21 degrees or warmer, and the flow temp is 28 degrees, of course the return temp is going to be no lower than the room temp! The puzzling thing is that the return temp is still much closer to the flow temp than the room temp. Now the advice from my installer is “turn the radiator TRV’s to max”. This they are already, on the maximum end stops. But now I wander now if the TRV’s are still interfering. I feel an urge to point my IR thermometer at some radiators now (and maybe remove the TRV regulators completely).

The deltaT is certainly one factor. The open question is "What is the Minimum Compressor Load"? Is it 0.5Amps, 1.3Amps, 1.8Amps, 2.3Amps? Because I've seen all of them dominate as a minimum output. The answer seems to be "it depends", because PID control parameters alone are not bringing the compressor load down to 0.5 Amps all the time. There seem to be additional interventions Last night for example, the COP was poor due to low deltaT, and yet the compressor refused to drop below 2.3Amps. During the leaving water climbup to the setpoint however, the COP performance was right on the published figures, but once the setpoint of 32 degrees was reached, the COP tanked. On previous nights, a setpoint of 32 degrees was absolutely humming along with a compressor current of 1.3Amps and a much better COP. I raised the setpoint of the Weather dependent curve yesterday evening, and the consequence on the minimum output is that it also increased. So the COP numbers in steady state have no opportunity to improve. I've reverted back to the previous weather curve. The "unknown variables" that affect minimum compressor load are yet to be uncovered. I'll continue to probe, and hopefully I'll discover those variables.

@@anthonydyer3939Delta T actually represents ‘load’ or lack of it.

There's definitely behaviours that can't be explained with a simple "keep the temperatures low, keep the heatpump running steady" piece of advice that the likes of HeatGeek seem to allude to.. I'm sure I'll uncover the secrets of heatpump operation and then I'll make another video.

You can look at the heatpump on a cool humid day. If you get condensation only on a portion of the outdoor heat exchanger fins then something is up. That’s the easy way to figure things out. But heatgeek approved installers are now going to be guaranteeing the expected SCOP that they provide you in the quote. They’ll carry out remedial actions if that number isn’t achieved. So in order to provide such a guarantee, they of course need to put the measuring equipment in that measures it. No doubt that is “open energy monitor” equipment. But heat pumps aren’t complex. We’re just scrutinising them a lot more because they are so much more expensive than legacy gas boilers - at the moment. But as you’ve seen, the business end of the heat pump really is a simple device. I think there’s a lot of scope to reduce material costs in the future.

I’ve not heard of that, but the text files are perfectly fine for this use. I haven’t dabbled in other file formats such as xml. I need to get my head around the advantages of each file format vs another. Tab separated files are easy to understand, but I’m told they are ‘primitive’ methods.