Air Source Heat Pumps
Discussion
I’m getting quotes on the above at the moment.
An 11KW double fan Mitsubishi system is around £13K, the govt incentives to fit the unit make the payback around 10 years.
The outside unit is huge, half the size of a double bed and needs to be placed on the patio. It needs to be a twin fan unit to cope with the energy demands of the house.
Various sales spiel has been given, (about fully removing gas as a fuel to my house etc) but I wanted to check if anyway had any pro’s or cons from experience on adopting air source.
The RHI scheme is about to change (I expect for the worse) which may kill this dead anyway.
Electricity is 5X the cost of gas but air source gives 3KW of heat benefit for every 1KW of input electricity, plus electricity is more of a secure fuel source moving forward.
I am amazed at some of the rubbish I’ve been told by those looking for an order but the principal of the technology is very attractive.
Any thoughts welcome.....
An 11KW double fan Mitsubishi system is around £13K, the govt incentives to fit the unit make the payback around 10 years.
The outside unit is huge, half the size of a double bed and needs to be placed on the patio. It needs to be a twin fan unit to cope with the energy demands of the house.
Various sales spiel has been given, (about fully removing gas as a fuel to my house etc) but I wanted to check if anyway had any pro’s or cons from experience on adopting air source.
The RHI scheme is about to change (I expect for the worse) which may kill this dead anyway.
Electricity is 5X the cost of gas but air source gives 3KW of heat benefit for every 1KW of input electricity, plus electricity is more of a secure fuel source moving forward.
I am amazed at some of the rubbish I’ve been told by those looking for an order but the principal of the technology is very attractive.
Any thoughts welcome.....
Part of the refit involves changing standard radiators for either bulky 3X core types or much larger double core types in place of current ones using elbow joints to join up the existing pipes (saving ripping floors up).
Bathrooms are exempted as not habitable rooms. 13mm bore, if your on microbore it needs replacing with 13mm.
Had warnings that you run it different to standard gas, it always needs to be on and does not run as hot. Biggest complaint is cold houses where people switch on and off for example, which is not how you run the ASHP system, low energy acheived only through constant running etc but noted on comment above.
House is assessed and measured for energy use and has to meet certain efficiency criteria to qualify (so that heat generated is not wasted).
Sales just want a sale, despite 2 visits still asking if I do or don’t have solar, no marks for attention to detail or my confidence in some of other claims made.
Govt offering £10K over 7 years to fit it though obviously appeals.
Bathrooms are exempted as not habitable rooms. 13mm bore, if your on microbore it needs replacing with 13mm.
Had warnings that you run it different to standard gas, it always needs to be on and does not run as hot. Biggest complaint is cold houses where people switch on and off for example, which is not how you run the ASHP system, low energy acheived only through constant running etc but noted on comment above.
House is assessed and measured for energy use and has to meet certain efficiency criteria to qualify (so that heat generated is not wasted).
Sales just want a sale, despite 2 visits still asking if I do or don’t have solar, no marks for attention to detail or my confidence in some of other claims made.
Govt offering £10K over 7 years to fit it though obviously appeals.
Water heating is a bone of contention with both companies that quoted. My solar PV heats a pressurised cylinder, we use no gas (other than cooking) between May and Oct.
So the gas use is loaded in winter.
So both sales people have seriously stated I only use gas half the year ‘so we can divide what you pay by 2 to give the true figure of use.’
Er, no.
In terms of noise, regs state 1M from neighbour boundary for siting. I get on with my neighbours so that won’t be happening. Luckily went to see one in operation and even though indoors, was a shock regarding noise.
Plus point was it sucked heat out of the room so you can see it working in real world.
Mitsubishi have water as transfer liquid meaning it should be cheaper to own the system.
Issue is, long after the installers disappear, I have to make sure this system works for my family and there is an air of double glazing sales about the whole thing, cold calling, incomplete info etc.....
So the gas use is loaded in winter.
So both sales people have seriously stated I only use gas half the year ‘so we can divide what you pay by 2 to give the true figure of use.’
Er, no.
In terms of noise, regs state 1M from neighbour boundary for siting. I get on with my neighbours so that won’t be happening. Luckily went to see one in operation and even though indoors, was a shock regarding noise.
Plus point was it sucked heat out of the room so you can see it working in real world.
Mitsubishi have water as transfer liquid meaning it should be cheaper to own the system.
Issue is, long after the installers disappear, I have to make sure this system works for my family and there is an air of double glazing sales about the whole thing, cold calling, incomplete info etc.....
Fuel saving is only £100 per year, just checked on calcs, so marginal. New system can accept direct PV feed so solar heating of hot water stays as is, concerned it may not be as hot tbh though on pure air source.
Govt give £11.5K incentive over 7 years not the figure I have above.
Hence 10 years to payback.
One of drivers for me is electricity has a good mix of sources, gas seems to be heading towards a footnote as a political football (maybe the real reason for those incentives).
I’d probably get £800 for the current boiler and cylinder, would have to loan the cash to cover the cost so 3% adds another chunk to payback.
May paint the external unit matt black and pretend I’m doing a remake of 2001......
Govt give £11.5K incentive over 7 years not the figure I have above.
Hence 10 years to payback.
One of drivers for me is electricity has a good mix of sources, gas seems to be heading towards a footnote as a political football (maybe the real reason for those incentives).
I’d probably get £800 for the current boiler and cylinder, would have to loan the cash to cover the cost so 3% adds another chunk to payback.
May paint the external unit matt black and pretend I’m doing a remake of 2001......
Paying less than £100 per month today for gas and electricity for the 3 bed, 3 story 1936 detached house!
Some interesting comments above, I’ll be honest I’m not convinced.
RHI we qualify, we are on mains gas.
I think it’s too marginal, the cold snap we just had, appreciate it’s a one off but would expect ashp to be chewing through electricity in those conditions.
Company is now looking to put us on hybrid system, heat only, for a fractional cost saving, any solution for a sale?
Some interesting comments above, I’ll be honest I’m not convinced.
RHI we qualify, we are on mains gas.
I think it’s too marginal, the cold snap we just had, appreciate it’s a one off but would expect ashp to be chewing through electricity in those conditions.
Company is now looking to put us on hybrid system, heat only, for a fractional cost saving, any solution for a sale?
Hi,
I never went for this in the end.
Like solar, I initiated the first contact with those offering installations and got the feeling the sales guys were just making stuff up to get a sale. One example, I asked for what I originally expected to be the small fan unit to be mounted above the garage on an external wall and the sales guy agreed. Inspection engineer rejected this add the sales guy stated he thought he would, couldn't trust anything after this.
My solar does a great job of negating gas use during summer but they just wanted rid of the pressurised cylinder to make way for their system etc.
Ultimately, the house is too marginal to benefit due to age and unlike solar the variables are unproven until long after youve spent the money.
Have a frindd with a new build though off the gas grid and it makes sense for him.
Get a few quotes, keep your eyes open and make sure you speak to other homeowners that have it would be my advice.
I never went for this in the end.
Like solar, I initiated the first contact with those offering installations and got the feeling the sales guys were just making stuff up to get a sale. One example, I asked for what I originally expected to be the small fan unit to be mounted above the garage on an external wall and the sales guy agreed. Inspection engineer rejected this add the sales guy stated he thought he would, couldn't trust anything after this.
My solar does a great job of negating gas use during summer but they just wanted rid of the pressurised cylinder to make way for their system etc.
Ultimately, the house is too marginal to benefit due to age and unlike solar the variables are unproven until long after youve spent the money.
Have a frindd with a new build though off the gas grid and it makes sense for him.
Get a few quotes, keep your eyes open and make sure you speak to other homeowners that have it would be my advice.
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