We had our viessmann 10kW HP fitted 1st week in November 2023 by heat geek installer. Our house is modern build over 5 levels, all floors block and beam with UFH throughout. Pump was installed open loop, no zoning or buffer tank with weather compensation. Flow temp is 34c at freezing. Home heated to 22c. Our overall scop from November to end of March 2024 was 4.4. Heating was 4.7 DHW 2.9. We have solar and 20kW home battery storage. Our average electricity cost is 9 pence so very cheap system to run.
I’m about to go for Viesmann on a new build. What impressed me about them was that all the calculations were done in Germany. They obviously know their stuff.
I think we need to face up to the fact that the “heat pump wizards” in this country are to rare, we need different people commissioning and snagging the system to the guy who is installing it.
This story is one that we hear about over and over again. Its no wonder that people have lost confidence in this whole transition. It should be fully expected that the companies installing these new systems, know what they are doing, but obviously from this example, many do not. Can you imagine going through this nightmare for 2 years, never mind the cost.
Depends who you blame. Blaming the transition or the government or the green agenda for the problem is passing the buck. The heating industry hasn't been optimising boiler efficiency for the two decades we've had condensing boilers. Badged condensing boilers installed and operated above dew point temperatures, never getting their claimed efficiencies. Not to blame engineers, but manufacturers and the training schemes. Even home owners for refusing to engage with the quality of their system and going bargain basement for everything.
Electricity suppliers say faulty meters are extremely rare. We had one massively over reading. After a long fight we got them to put a comparison meter in showing it was massively out. The engineer confirmed its not as rare as the suppliers like to pretend.
I agree with you that skills are a problem in the industry. I've contacted a bunch of MCS companies and they're all proposing heat pumps which are massively oversized when compared to my actual, measured, gas usage over 17 years. That oversizing extends to the heat loss surveys too. All of these suggest a heat loss of 10 - 12 kW when I have never needed more than 5 kW to heat my house, even on the coldest days and bear in mind that I'm running my combi boiler at 35 C, that is a long way from optimal, and we're warm.
On NG at 35deg flow and only needing 5kw, and the cost difference of a heatpump why change it? If you don't spend much and you keep warm, why change, the average life of a boiler is much more than 8 years when correctly installed, I regularly service boilers that are over twenty years old and on the flip side, while working for a major manufacturer we invalidated warranties (6 to12 years) at two years because the system is filthy, the customers will never pay for the required flush and certification to reinstate the Warranty and no doubt blame the boiler when it finally dies. Save your money, have a holiday and run your gas boiler for less than the heat pump, it's only carbon! Trees love it!!
@@551moley Why change the gas boiler? Two reasons 1) global warming is threat to all of us: Margret Thatcher warned of this in her address to the UN in 1989 2) at the manufacturer's stated efficiencies of both gas boilers and heat pumps I can save money by converting to a heat pump.
@@edc1569How on earth is a customer supposed to determine which installers are cowboys and which ones are genuinely experienced experts, without becoming an expert themselves? Also, professionals in the field can become very defensive when questioned.
Interesting story to hear. I'm fortunate in that I get the points about weather compensation and settings etc so I think I'm prepared for when we get a heat pump installed. Also pondering whether there's a career opening there if these skills are rare and I do understand it
Like with many house issues if its not doing what you think it should believe in yourself and get a second opinion early on. Open energy forum is full of knowlagable helpful people and can help educate and fault find. But getting a second engineer in is probably money we'll spent. Glad you got what you should have, all be it 2 years late and will too much stress.
These videos invariably show expensive houses with ample space for plant rooms and spare external space for outdoor units. More feedback on how the majority of properties, that are far smaller, can adopt heat pumps (that must suit the occupants lifestyles) would be far more beneficial
Although I like the idea of heat pumps , the really big problem is the difference in price between natural gas and electricity. Very few heat pump setups deliver 400% COP in the real world , which they need to do to even be price competitive fuel cost wise. The realistic COP return in a non super insulated house is more like 2.5 to 3, and the fact that tanked stored hot water is required, rather than hot water on demand from a gas combi boiler, adds to this problem of efficiency in real terms.
Agree - a simple government 'nudge' would be to scrap the VAT per kWHr on electricity, and get the money back by doubling it on gas for domestic tariffs. Won't close the gap between the fuels entirely given typical COP values, but sends a message.
@@roberthuntley1090 I'm not sure making gas more expensive by taxation is a vote winner. I think the possibility of subsidised / low tariff electricity via a dedicated separately metered supply to the heat pump is a better idea. When electricity was first mass distributed in the late 19th/ early 20th century, there was a lower rate for lighting than for other electricity use : it would be the same concept in reverse.
@@lewisbrand The govt. is broke, so I was looking for something that was broadly revenue neutral (based on the Ofgem dual fuel consumption figures for a typical house) and simple to implement. Separately measuring lighting would need an additional meter (and not cover table lamps etc. running of the ring main), and given the wide spread use of LED lights the consumption for that is going to be a very small percentage of the total use anyway. Agree that politics will be an issue, but after the General Election whoever is in power will have 5 years for the public to get used to (forget?) abut the change.
@@roberthuntley1090 the cost of a brand new single phase electricity meter is between £10 and £25 on the open market, depending whether it a smart meter or not. Given the fact that the "broke" government is already willing to subsidise heat pump installations to the tune of £7,500, the cost of a Henley block and a dedicated meter for a heat pump is neither here nor there cost wise. I was advocating a seperate meter for the heat pump ; not lighting ( as was done in the past ), it was just an example of differential pricing practice that used to happen in the past. There already exist differential pricing between households and businesses ; often with huge differences, like 60p per KWH, and £2.50 per day standing charge, and if you wish the wide adoption of heat pumps, then business as well as households need dedicated lower tariff supplies for heat pumps.
@@roberthuntley1090 I wasn't advocating a seperate meter for lighting, just one for heat pumps. You would only need to reduce the cost per KWH by 10p to fill the gap between heat pumps and gas ; but this would also need to be available to businesses to promote widespread adoption of heat pumps. My analogy with differential pricing structures was an example from the past : I am advocating dedicated meters for heat pumps, not lighting. New meters are very cheap these days , between £10 and £25 depending on whether they are smart or not, and given the government is happy to subsidise new heat pump installations to the tune of £7.500 ,I don't think a Henley block and seperate meter is a big deal.
Activated and tailored the weather compensation, lowered the maximum flow temperature, reduced the setback, balanced the system, replaced a broken pump that was always on and a few more minor settings. Importantly, other than the pump there was nothing that couldn't have been done at the time of installation and it has halved the running costs.
Ive been installing heatpumps initially geo systems 20 years . It's only the start of the problems think people competent to fit is a problem just wait till it need repairing in years to come ... Very few people out there with right skillset... so likely a lot of very easily repairable machines will be bined as a consequence...
Well I tick a few boxes, I'm building a new house ICF and under floor, I've installed probably 70 to 100 heat pumps across the full range of houses, starter homes to multi million £ holiday homes, I've done many different manufacturers training courses, Mitsubishi, Worcester, Sanyo and a couple more. Despite quite a bit of pressure to go with a heatpump, It's a "Hell No" from me! Funnily enough the only positive for a Heat Pump is not having to deal with Calor! Total twats to deal with and Flogas is much worse (23 years as a customer). I'm going with Gas! essentially the house will be "heatpump ready" the cost difference at trade prices is about £5k between a Worcester 12kw LPG and smaller heatpump, Worcester currently guarantee 93% efficiency for some boilers, so I dont see a massive price difference over the next few years. At 56 I'm done with the gas industry, Im having a year off to build the house and don't really plan on going back into it?
Also manufacturers don't care about distributing knowledge required to keep older machines working or to supply parts just look up prices of new compressor or pcb board...a heatpump anywhere close to 10 would be economic rightoff as too risky to put expensive part in incase something else were to fail
I have seen a heat pump installation by a so called MCS certified company that was that shocking you would have thought a poor diy er had fitted it although im nbot sure they could have done it that bad. the problem is a piece of paper or certificate does not mean you will get a good job. It seems that MCS registered companies are so busy they are taking on subbies to install and then signing off their work without checking it. I have been in the construction/ water industry installing large commercial pumps for nearly 30 years and now i am approaching the end of my career i refuse to take anymore of the pointless courses that just prove you can listen, and remember. The worse of all is the CSCS and sure MCS is close behind it. My advice to anyone getting a heat pump is do your homework and dont just use a MCS registered person without asking for some references from them, or hopefully by now you now someone who has had one isntalled that does work Thankfullyi have one on a 220 year old solid stone building with radiators that is now far cheaper to run than the old oil boiler and i feel i may have helped to attempt to put a smile on Greta's face!
I’m a gas engineer. Everyday I see boilers sized and fitted incorrectly. Luckily you can get away with it most the time. Good luck when it comes to fitting all these heat pumps. If they go ahead and try to swap all gas boilers to heat pumps it will be absolute carnage out there. I think you’d be mad to fit a heat pump unless you have no other viable option or your building a new build house.
@@jamiebrown8437 Well it is always good to engage. Do you see the fundamental problem as a low skilled gas boiler installer industry jumping on the heat pump bonanza and leaving poor performing installations and stranded customers in their wake?
MCS certification is meaningless box ticking crap, forget the BUS grant, it just inflates the price - YOU won't get £7.5k off - that (tax payer's) money goes to the plumber. My advice is keep your boiler for Hot Water and VERY cold days and install air conditioning units to heat your house. Most heat pumps in Sweden are a/c units - why us Brits love heating up water instead of the room is beyond me. A/C units can be installed in one day, cost a small fraction of air to water heat pumps, are more efficient and responsive and don't have to replace the gas boiler so you have backup.
- Same generation and manufacturer A2W is always more efficient than A2A. - UFH creates better vertical heat distribution, that achieves better comfort @ lower cost. - UFH doesn't make (audible) noise in the rooms. Air has very low specific heat compared to water, you need to circulate a lot of air, if that's your heat transport fluid. UFH solves this, as the final efficiently (flow) transferred heat (by water) is radiated through a huge surface. Even if the refrigerant circuits are as efficient in A2A (they don't, also, they the use refrigerants with higher GWP), the AC indoors ventilators needs more power than circulating pumps of UFH. - A2A are more responsive, yes, but you should never need more responsive system than a weather compensated UFH. If you do need, you are ventillating through windows, and that's another topic in itself. - Your body loses most of the heat through radiation, but it also gets most of the heat from the env through radiation. As described earlier, AC does not radiate much heat. Heating the air is easy, but walls will radiate cold (more precisely won't radiate heat) which will feel cold. So responsiveness is a crap thing to measure a system by. You should not let the walls cool down. All in all, A2A is good for renovations, but I wouldn't advise it in new builds. Also, in Hungary, regulation requires central heating, so multiple ACs are not an option as THE only heating system. I don't know about UK, but I can imagine similar regulations. Sadly, grants get swallowed by the contractors in Hungary too...
If you live in north of Scotland FFS DO NOT FIT AN AIR SOURCE HEAT PUMP... WHY, because from 10 degrees and lower they are inefficient, at 0 to - 5 they are very inefficient and at - 6 and lower they burn electricity at such a rate that the old electric meter makes more notice than the pump ITSELF for the speed it goes arohnd!! ..To only heat the hot water(no central heating system is fitted) for one person cost 2500 Kwh units for 5 months (using oil to do the same cost 5x less) .. Totally rediculous unless the Kwh unit price is 5p per unit or lower..
@@edc1569And that’s where you make the common mistake. Scandinavian countries have much less moisture in their atmosphere. It’s the rain laden winter air that’s the problem, not the ambient temperature
@@hughmarcus1 Wet and warm in the UK nicely in the dew point! I've had new AS pumps freeze solid trying to commission them in winter, they need heat in the system to do the defrost cycle, that often comes from the electric backup.
@@551moleyYes & that’s a point of misunderstood. The ‘thaw’ cycle is usually a large internal immersion heater. That’s just going to burn electricity 😬
Not sure it is not anecdotal. Look up Keymark certificates. Most modern heat pumps have a COP of greater than 2.5 @ -7 Celsius, depending on the setting an heat pump, some even higher than 3. These are lab test results. Keymark does take power consumption of resistive heating elements into account. Not just the a backup heater, but resistive tapes around expansion valve and other ones in the refrigerant cycle. Okay, humid environments can be worse, the test settings does not mimic that. And thaw cycles works by circulation previously heated water in modern heat pumps, NOT by large immersion heaters. I know companies that do not install any backup immersion heaters at all in the heating circuit (maybe in the DHW tank where there are many residents, but the pump cannot utilise that for thaw cycle, as the diverter valve is set to heating during thaw cycles) and their systems go above 3.5 SCOP in England. I agree, it could be that gas can be cheaper in Scotland, but to say that they are "very inefficient" when a well planned total system should be still above at 2.5 SCOP (and that's a safe bet) is nuts.
We had our viessmann 10kW HP fitted 1st week in November 2023 by heat geek installer. Our house is modern build over 5 levels, all floors block and beam with UFH throughout. Pump was installed open loop, no zoning or buffer tank with weather compensation. Flow temp is 34c at freezing. Home heated to 22c. Our overall scop from November to end of March 2024 was 4.4. Heating was 4.7 DHW 2.9. We have solar and 20kW home battery storage. Our average electricity cost is 9 pence so very cheap system to run.
So envious, I’m trying to get a heat geek to fit a Viessmann. I don’t want Vailant or Daikin.
Where do you live, roughly..
@@plasticjock1090 Staffordshire.
I’m about to go for Viesmann on a new build. What impressed me about them was that all the calculations were done in Germany. They obviously know their stuff.
I think we need to face up to the fact that the “heat pump wizards” in this country are to rare, we need different people commissioning and snagging the system to the guy who is installing it.
This story is one that we hear about over and over again. Its no wonder that people have lost confidence in this whole transition. It should be fully expected that the companies installing these new systems, know what they are doing, but obviously from this example, many do not. Can you imagine going through this nightmare for 2 years, never mind the cost.
Depends who you blame.
Blaming the transition or the government or the green agenda for the problem is passing the buck.
The heating industry hasn't been optimising boiler efficiency for the two decades we've had condensing boilers. Badged condensing boilers installed and operated above dew point temperatures, never getting their claimed efficiencies.
Not to blame engineers, but manufacturers and the training schemes. Even home owners for refusing to engage with the quality of their system and going bargain basement for everything.
She talks like her old pump operated, non-stop, all day and it took a determined expert to make it stop. Good video.
Electricity suppliers say faulty meters are extremely rare. We had one massively over reading. After a long fight we got them to put a comparison meter in showing it was massively out. The engineer confirmed its not as rare as the suppliers like to pretend.
I agree with you that skills are a problem in the industry.
I've contacted a bunch of MCS companies and they're all proposing heat pumps which are massively oversized when compared to my actual, measured, gas usage over 17 years. That oversizing extends to the heat loss surveys too. All of these suggest a heat loss of 10 - 12 kW when I have never needed more than 5 kW to heat my house, even on the coldest days and bear in mind that I'm running my combi boiler at 35 C, that is a long way from optimal, and we're warm.
I’d avoid anyone touting MCS, most of them are cowboys. Just keep looking, you’ll find someone who knows what they’re doing eventually.
On NG at 35deg flow and only needing 5kw, and the cost difference of a heatpump why change it? If you don't spend much and you keep warm, why change, the average life of a boiler is much more than 8 years when correctly installed, I regularly service boilers that are over twenty years old and on the flip side, while working for a major manufacturer we invalidated warranties (6 to12 years) at two years because the system is filthy, the customers will never pay for the required flush and certification to reinstate the Warranty and no doubt blame the boiler when it finally dies.
Save your money, have a holiday and run your gas boiler for less than the heat pump, it's only carbon! Trees love it!!
@@551moley Why change the gas boiler? Two reasons 1) global warming is threat to all of us: Margret Thatcher warned of this in her address to the UN in 1989 2) at the manufacturer's stated efficiencies of both gas boilers and heat pumps I can save money by converting to a heat pump.
@@edc1569How on earth is a customer supposed to determine which installers are cowboys and which ones are genuinely experienced experts, without becoming an expert themselves? Also, professionals in the field can become very defensive when questioned.
Interesting story to hear. I'm fortunate in that I get the points about weather compensation and settings etc so I think I'm prepared for when we get a heat pump installed. Also pondering whether there's a career opening there if these skills are rare and I do understand it
Really useful information and the questions didscussed were so pertinent - many thanks from someone trying to do the homework🙃
Like with many house issues if its not doing what you think it should believe in yourself and get a second opinion early on. Open energy forum is full of knowlagable helpful people and can help educate and fault find. But getting a second engineer in is probably money we'll spent. Glad you got what you should have, all be it 2 years late and will too much stress.
Great upload and really enjoyed a realistic and honest conversation, however the video title should read POORLY COMMISSIONED HEAT PUMP ?
Should have just asked a Building Services Engineer, for an hour of his time.
These videos invariably show expensive houses with ample space for plant rooms and spare external space for outdoor units. More feedback on how the majority of properties, that are far smaller, can adopt heat pumps (that must suit the occupants lifestyles) would be far more beneficial
Wall mounting of the heat pumps and use of thermal stores instead of hot water tanks can minimise the space needed.
Spoiler : It wasn't on weather compensation & wasn't balanced & poor set up caused Scop 1.6 ! Just fixing these doubled scop. 2nd half is useful too.
Although I like the idea of heat pumps , the really big problem is the difference in price between natural gas and electricity. Very few heat pump setups deliver 400% COP in the real world , which they need to do to even be price competitive fuel cost wise. The realistic COP return in a non super insulated house is more like 2.5 to 3, and the fact that tanked stored hot water is required, rather than hot water on demand from a gas combi boiler, adds to this problem of efficiency in real terms.
Agree - a simple government 'nudge' would be to scrap the VAT per kWHr on electricity, and get the money back by doubling it on gas for domestic tariffs. Won't close the gap between the fuels entirely given typical COP values, but sends a message.
@@roberthuntley1090 I'm not sure making gas more expensive by taxation is a vote winner. I think the possibility of subsidised / low tariff electricity via a dedicated separately metered supply to the heat pump is a better idea. When electricity was first mass distributed in the late 19th/ early 20th century, there was a lower rate for lighting than for other electricity use : it would be the same concept in reverse.
@@lewisbrand The govt. is broke, so I was looking for something that was broadly revenue neutral (based on the Ofgem dual fuel consumption figures for a typical house) and simple to implement. Separately measuring lighting would need an additional meter (and not cover table lamps etc. running of the ring main), and given the wide spread use of LED lights the consumption for that is going to be a very small percentage of the total use anyway.
Agree that politics will be an issue, but after the General Election whoever is in power will have 5 years for the public to get used to (forget?) abut the change.
@@roberthuntley1090 the cost of a brand new single phase electricity meter is between £10 and £25 on the open market, depending whether it a smart meter or not. Given the fact that the "broke" government is already willing to subsidise heat pump installations to the tune of £7,500, the cost of a Henley block and a dedicated meter for a heat pump is neither here nor there cost wise. I was advocating a seperate meter for the heat pump ; not lighting ( as was done in the past ), it was just an example of differential pricing practice that used to happen in the past. There already exist differential pricing between households and businesses ; often with huge differences, like 60p per KWH, and £2.50 per day standing charge, and if you wish the wide adoption of heat pumps, then business as well as households need dedicated lower tariff supplies for heat pumps.
@@roberthuntley1090 I wasn't advocating a seperate meter for lighting, just one for heat pumps. You would only need to reduce the cost per KWH by 10p to fill the gap between heat pumps and gas ; but this would also need to be available to businesses to promote widespread adoption of heat pumps. My analogy with differential pricing structures was an example from the past : I am advocating dedicated meters for heat pumps, not lighting. New meters are very cheap these days , between £10 and £25 depending on whether they are smart or not, and given the government is happy to subsidise new heat pump installations to the tune of £7.500 ,I don't think a Henley block and seperate meter is a big deal.
Air tight paint on the walls. OUCHHH!!!. Who came up with that idea? Best to have walls breathing with ventilation.
What size heat pump did you have and what size did you replace it with?
Same heat pump, just optimised now
So what settings had to be changed?
Activated and tailored the weather compensation, lowered the maximum flow temperature, reduced the setback, balanced the system, replaced a broken pump that was always on and a few more minor settings. Importantly, other than the pump there was nothing that couldn't have been done at the time of installation and it has halved the running costs.
Ive been installing heatpumps initially geo systems 20 years .
It's only the start of the problems think people competent to fit is a problem just wait till it need repairing in years to come ...
Very few people out there with right skillset... so likely a lot of very easily repairable machines will be bined as a consequence...
Well I tick a few boxes, I'm building a new house ICF and under floor, I've installed probably 70 to 100 heat pumps across the full range of houses, starter homes to multi million £ holiday homes, I've done many different manufacturers training courses, Mitsubishi, Worcester, Sanyo and a couple more.
Despite quite a bit of pressure to go with a heatpump, It's a "Hell No" from me!
Funnily enough the only positive for a Heat Pump is not having to deal with Calor! Total twats to deal with and Flogas is much worse (23 years as a customer).
I'm going with Gas! essentially the house will be "heatpump ready" the cost difference at trade prices is about £5k between a Worcester 12kw LPG and smaller heatpump, Worcester currently guarantee 93% efficiency for some boilers, so I dont see a massive price difference over the next few years.
At 56 I'm done with the gas industry, Im having a year off to build the house and don't really plan on going back into it?
Also manufacturers don't care about distributing knowledge required to keep older machines working or to supply parts just look up prices of new compressor or pcb board...a heatpump anywhere close to 10 would be economic rightoff as too risky to put expensive part in incase something else were to fail
nvq level 2 plumbing and a three day course =accredited installer
There in lies the problem..
PLEASE don't refer to these people as Engineers, they are fitters/plumbers or technicians at best.
I have seen a heat pump installation by a so called MCS certified company that was that shocking you would have thought a poor diy er had fitted it although im nbot sure they could have done it that bad. the problem is a piece of paper or certificate does not mean you will get a good job. It seems that MCS registered companies are so busy they are taking on subbies to install and then signing off their work without checking it.
I have been in the construction/ water industry installing large commercial pumps for nearly 30 years and now i am approaching the end of my career i refuse to take anymore of the pointless courses that just prove you can listen, and remember. The worse of all is the CSCS and sure MCS is close behind it.
My advice to anyone getting a heat pump is do your homework and dont just use a MCS registered person without asking for some references from them, or hopefully by now you now someone who has had one isntalled that does work
Thankfullyi have one on a 220 year old solid stone building with radiators that is now far cheaper to run than the old oil boiler and i feel i may have helped to attempt to put a smile on Greta's face!
Nobody wants to get their hands dirty or do anything real, hence the massive shortage of practical skills.
I’m a gas engineer. Everyday I see boilers sized and fitted incorrectly. Luckily you can get away with it most the time. Good luck when it comes to fitting all these heat pumps. If they go ahead and try to swap all gas boilers to heat pumps it will be absolute carnage out there. I think you’d be mad to fit a heat pump unless you have no other viable option or your building a new build house.
Let's keep buying gas then....
If you were a ‘heating engineer’ you might have a valid viewpoint.
How would you like me to respond Norm
Luckily the gas will never run out and we can just keep giving Putin/biden/qatar whatever they demand for it.
@@jamiebrown8437 Well it is always good to engage. Do you see the fundamental problem as a low skilled gas boiler installer industry jumping on the heat pump bonanza and leaving poor performing installations and stranded customers in their wake?
MCS certification is meaningless box ticking crap, forget the BUS grant, it just inflates the price - YOU won't get £7.5k off - that (tax payer's) money goes to the plumber. My advice is keep your boiler for Hot Water and VERY cold days and install air conditioning units to heat your house. Most heat pumps in Sweden are a/c units - why us Brits love heating up water instead of the room is beyond me. A/C units can be installed in one day, cost a small fraction of air to water heat pumps, are more efficient and responsive and don't have to replace the gas boiler so you have backup.
- Same generation and manufacturer A2W is always more efficient than A2A.
- UFH creates better vertical heat distribution, that achieves better comfort @ lower cost.
- UFH doesn't make (audible) noise in the rooms. Air has very low specific heat compared to water, you need to circulate a lot of air, if that's your heat transport fluid. UFH solves this, as the final efficiently (flow) transferred heat (by water) is radiated through a huge surface. Even if the refrigerant circuits are as efficient in A2A (they don't, also, they the use refrigerants with higher GWP), the AC indoors ventilators needs more power than circulating pumps of UFH.
- A2A are more responsive, yes, but you should never need more responsive system than a weather compensated UFH. If you do need, you are ventillating through windows, and that's another topic in itself.
- Your body loses most of the heat through radiation, but it also gets most of the heat from the env through radiation. As described earlier, AC does not radiate much heat. Heating the air is easy, but walls will radiate cold (more precisely won't radiate heat) which will feel cold. So responsiveness is a crap thing to measure a system by. You should not let the walls cool down.
All in all, A2A is good for renovations, but I wouldn't advise it in new builds.
Also, in Hungary, regulation requires central heating, so multiple ACs are not an option as THE only heating system. I don't know about UK, but I can imagine similar regulations.
Sadly, grants get swallowed by the contractors in Hungary too...
If you live in north of Scotland FFS DO NOT FIT AN AIR SOURCE HEAT PUMP... WHY, because from 10 degrees and lower they are inefficient, at 0 to - 5 they are very inefficient and at - 6 and lower they burn electricity at such a rate that the old electric meter makes more notice than the pump ITSELF for the speed it goes arohnd!! ..To only heat the hot water(no central heating system is fitted) for one person cost 2500 Kwh units for 5 months (using oil to do the same cost 5x less) .. Totally rediculous unless the Kwh unit price is 5p per unit or lower..
Every Scandinavian home owner is chuckling to themselves :)
@@edc1569And that’s where you make the common mistake. Scandinavian countries have much less moisture in their atmosphere. It’s the rain laden winter air that’s the problem, not the ambient temperature
@@hughmarcus1 Wet and warm in the UK nicely in the dew point! I've had new AS pumps freeze solid trying to commission them in winter, they need heat in the system to do the defrost cycle, that often comes from the electric backup.
@@551moleyYes & that’s a point of misunderstood.
The ‘thaw’ cycle is usually a large internal immersion heater. That’s just going to burn electricity 😬
Not sure it is not anecdotal.
Look up Keymark certificates. Most modern heat pumps have a COP of greater than 2.5 @ -7 Celsius, depending on the setting an heat pump, some even higher than 3. These are lab test results.
Keymark does take power consumption of resistive heating elements into account. Not just the a backup heater, but resistive tapes around expansion valve and other ones in the refrigerant cycle. Okay, humid environments can be worse, the test settings does not mimic that.
And thaw cycles works by circulation previously heated water in modern heat pumps, NOT by large immersion heaters. I know companies that do not install any backup immersion heaters at all in the heating circuit (maybe in the DHW tank where there are many residents, but the pump cannot utilise that for thaw cycle, as the diverter valve is set to heating during thaw cycles) and their systems go above 3.5 SCOP in England.
I agree, it could be that gas can be cheaper in Scotland, but to say that they are "very inefficient" when a well planned total system should be still above at 2.5 SCOP (and that's a safe bet) is nuts.