Posted by: @johnmo

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Some info on buffers

Thanks, v helpful. They also have this other page covering it slightly differently: https://www.kensaheatpumps.com/installer/tech-focus-part-2/
 

Posted by: @johnmo

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If you don't mind me asking, are those prices after the grant? .... Assume you need radiators also?

Yes, £6500 with Aira after grant and £10,500 with Heat Geek. 6 or 7 new radiators with both. Self install is not something I'd be comfortable with doing.
 

Have you tried Grant? They use local plumbers to do the work and the design and commissioning is done by people that know what they are doing.there nothing magically about R290, I would be quite comfortable going R32. Design of system is the important bit.

Posted by: @johnmo

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Have you tried Grant? They use local plumbers to do the work and the design and commissioning is done by people that know what they are doing.there nothing magically about R290, I would be quite comfortable going R32. Design of system is the important bit.

I take it that Grant don't do R290? My concern about R32 is that it has 200 times the global warming potential.
 

@ivanopinion I have wondered about this business of global warming potential of the various gases used. I think there is only a potential of releasing any of the gas into the atmosphere if there were a leak and that during normal use, no gas should be released. The actual quantity of gas used is, I am given to understand, relatively small. I’m also told that the gas is extracted safely at the end of life for the pump. Of course, I may be living in cloud cuckoo land and I have it completely wrong? Regards, Toodles.

@toodles I was assuming the same thing. So, it might not be an issue. I'm not sure how often the refrigerant leaks.

@ivanopinion I heard of a batch of Daikin heat pumps that left the factory short measured on R32, but, that was a case of underfilling rather than leakage I believe. Mind you, I do think twice before I light up the butane powered barbecue these days - so I suppose this is due to heightened awareness. 🫘😉. Regards Toodles.

Posted by: @ivanopinion

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I take it that Grant don't do R290? My concern about R32 is that it has 200 times the global warming potential.

Grant not looked at there current line up for a while so don't know.
You need to have a leak for the global warming effect to take place. How many fridges leak their gas away in the 20 years, they sit in a kitchen? A monobloc heat pump should be no different it's just a little bigger.
R290 is basically propane, so you have restrictions on location.
SCoP CoP are very similar R290 or R32, you can heat to 70 degrees with R290 and around 60 with R32. Do you need the additional 10 degs, most likely not. Good chance your paying an additional £1 to £1.5k for R290 over R32, no idea why as the components used to make the heat pump are almost identical.

Just to add a bit of my experience with Aira.

Their sales team is quite slick and very efficient. Within 1 week I had quote at a good price, and another week later a heat loss & design study was done. Everything was well considered and detailed . I was very excited to go ahead, as they seem to really know their stuff plus the comfort guarantee takes a lot of concern of the table. They specced the 8kw and a buffer tank. Very very good experience before install, way better than other (4 quotes + octopus). Very good price for a great looking system.

Installation was booked in promptly and 3 installation crews turned up on time, all good communication and friendly. Professional staff.

Then unfortunately things went south quite quickly...Within 30 minutes the install crew had identified a few flaws in the survey:

- surveyor forgot to add legs in the dimensions for the pump, adding 40cm. So the pump would now block my window view and opening.

- surveyor forgot about a few cable runs from ASHP to tank as well as a new consumer unit requiring its own power to the tank. Due to my house design (ASHP , water tank, buffer tank and grid meter all at opposite ends of the house ) those cable runs became impossible to run.

- bizarly the surveyor did not consider the internal pipework ; the installers thought all pipework to buffer had to be upgraded to 28mm , whereas surveyor though 22mm was enough).

They left after an hour . Real shame as I was keen on their system but the surveyor clearly needed more experience. I was never contacted after for any form of debrief/ what went wrong type conversation which I still find odd, as it must've cost them quite a lot.

So can't comment on their system working, but other than not installing it was great.

@pie_eater I hope they wrote up the experience to use in their training sessions? Toodles.

Posted by: @pie_eater

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Just to add a bit of my experience with Aira.

Their sales team is quite slick and very efficient. Within 1 week I had quote at a good price, and another week later a heat loss & design study was done. Everything was well considered and detailed . I was very excited to go ahead, as they seem to really know their stuff plus the comfort guarantee takes a lot of concern of the table. They specced the 8kw and a buffer tank. Very very good experience before install, way better than other (4 quotes + octopus). Very good price for a great looking system.

Installation was booked in promptly and 3 installation crews turned up on time, all good communication and friendly. Professional staff.

Then unfortunately things went south quite quickly...Within 30 minutes the install crew had identified a few flaws in the survey:

- surveyor forgot to add legs in the dimensions for the pump, adding 40cm. So the pump would now block my window view and opening.

- surveyor forgot about a few cable runs from ASHP to tank as well as a new consumer unit requiring its own power to the tank. Due to my house design (ASHP , water tank, buffer tank and grid meter all at opposite ends of the house ) those cable runs became impossible to run.

- bizarly the surveyor did not consider the internal pipework ; the installers thought all pipework to buffer had to be upgraded to 28mm , whereas surveyor though 22mm was enough).

They left after an hour . Real shame as I was keen on their system but the surveyor clearly needed more experience. I was never contacted after for any form of debrief/ what went wrong type conversation which I still find odd, as it must've cost them quite a lot.

So can't comment on their system working, but other than not installing it was great.

By that point they are in a legally binding agreement I thought, they should have their MCS certificate withdrawn.

 

@pie_eater Did they walk away to re-asses or have they cancelled the contract? I have signed with Aira and have had my heat loss survey. They are working on the design and applying for planning on my behalf we need the 12kW unit.