Is A2A to be included in the BUS grant spring 2025 ?

[Fueltheburn]

Hey Mart,

That is a surprise given your concise replies in the forum.



We had a very cold night last night and the resistive heating was on through the vanilla slot to offset some gas use which it did nicely. How does people with A2A systems fair in the sub zero days - I appreciate the CoP will drop but typically by how much ? I noted the dew point was minus 1 last night for us so this morning the cars where free of ice - I presume that would mean less defrost cylces for a hp and therefore improve the operation?

Moxi

1850s granite house with circa 70+mm of celotex/kingspan. A2A heatpump is our main source of heat that is situated in the living room. It blows from the living room into the kitchen and upstairs. Downstairs bathroom is electric towel rail. 2 of 4 bedrooms upstairs have Rointe D series smarts rads. Most downstairs rooms have ceramic filler in the paintwork which helps with comfort.

Our pipework for the central heating failed and I refused to pay £16k for using the same shoddy pipework and rads for an A2W HP. So I stripped out the rads and turn off the heating side of the oil combi boiler. The boiler just does hot water now.
The A2A pump is. 6kW unit and manages to heat the house without too much issue for about 9 months of the year. We heat the house with A2A to 19.5C all day, then drop to 18 at 10pm. The upstairs rads are set to 18C and on all day.

The A2A has been in for a year since October. December to Feb is where it needs additional help from a log burner for exactly the reason you point out. The high humidity here causes the matrix to freeze around the 1C mark.

Once we have the second unit (circa 4kW) installed upstairs, I think the shared load will lower the defrost cycles and possibly negate the need for the log burner during the coldest months in Aberdeenshire.

Wish I had done it before. It filters the air, reduces condensation (very important in old house) and we no longer get headaches from the radiators being on.








Even with an old school meter at £0.24/unit, bills are roughly £1500/yr - FIT cheques. This number is coming down further.

Just waiting for the A2A to be included in the grants. This is why I kept my oil boiler

[Adokforme]

Hey Mart,

That is a surprise given your concise replies in the forum.



We had a very cold night last night and the resistive heating was on through the vanilla slot to offset some gas use which it did nicely. How does people with A2A systems fair in the sub zero days - I appreciate the CoP will drop but typically by how much ? I noted the dew point was minus 1 last night for us so this morning the cars where free of ice - I presume that would mean less defrost cylces for a hp and therefore improve the operation?

Moxi

1850s granite house with circa 70+mm of celotex/kingspan. A2A heatpump is our main source of heat that is situated in the living room. It blows from the living room into the kitchen and upstairs. Downstairs bathroom is electric towel rail. 2 of 4 bedrooms upstairs have Rointe D series smarts rads. Most downstairs rooms have ceramic filler in the paintwork which helps with comfort.

Our pipework for the central heating failed and I refused to pay £16k for using the same shoddy pipework and rads for an A2W HP. So I stripped out the rads and turn off the heating side of the oil combi boiler. The boiler just does hot water now.
The A2A pump is. 6kW unit and manages to heat the house without too much issue for about 9 months of the year. We heat the house with A2A to 19.5C all day, then drop to 18 at 10pm. The upstairs rads are set to 18C and on all day.

The A2A has been in for a year since October. December to Feb is where it needs additional help from a log burner for exactly the reason you point out. The high humidity here causes the matrix to freeze around the 1C mark.

Once we have the second unit (circa 4kW) installed upstairs, I think the shared load will lower the defrost cycles and possibly negate the need for the log burner during the coldest months in Aberdeenshire.

Wish I had done it before. It filters the air, reduces condensation (very important in old house) and we no longer get headaches from the radiators being on.








Even with an old school meter at £0.24/unit, bills are roughly £1500/yr - FIT cheques. This number is coming down further.

Just waiting for the A2A to be included in the grants. This is why I kept my oil boiler

Thanks for posting @ Fueltheburn that's quite some leap of faith you've taken there, not to different from our journey into A2A although our property is compact, modern and much further south compared to yours so will be great to learn how it all goes in the final leg.
It was great removing all the radiators and pipework paraphernalia so decluttering walls etc for when redecorating, not to mention a healthy return from the recycling aspect.
I also fitted a Rointe electric towel radiator https://www.heatershop.co.uk/rointe-mil ... n?cat=9938 but in my sisters property and they love it. The addition of a 1 kW fan heater in combination with it being an added bonus, to use or not depending on temperatures outside etc. Wish I'd come across when completing ours although tempted to replace existing plain electric rad in ensuite with one due to it not being quite as cosy as we should like at times.
I doubt there could be a much more severe test than your place given it's age and location so if you can make A2A hp's a success then what an example for others to follow.
I wish you every success going forward and look forward to reading more in time, should you choose to enlighten us.

[Stinsy]

I've been watching my A2A closely during the unusually cold snap we are currently experiencing.

Firstly it is clear as ever that the "7kW" unit I have is oversized for my house. It was sized for cooling the heating part worked beyond my expectation. We haven't seen positive temperatures for a week and we've had overnight lows of -8℃ or below several nights in a row.

Defrost cycles are very clearly linked to humidity rather than temperature. When it is overcast and particularly when it is snwing, the A2A defrosts every hour or two. Today is cold, crisp, and sunny. The A2A defrosted at c. 6am and 9am, it is getting on for 2pm now and we're yet to have a third.

CoP is impossible to calculate. However YTD I've put c. 180kWh through the A2A and 200kWh through the resistive heaters, and I have a warm house!

[Mart]

Hey Mart,

That is a surprise given your concise replies in the forum.



We had a very cold night last night and the resistive heating was on through the vanilla slot to offset some gas use which it did nicely. How does people with A2A systems fair in the sub zero days - I appreciate the CoP will drop but typically by how much ? I noted the dew point was minus 1 last night for us so this morning the cars where free of ice - I presume that would mean less defrost cylces for a hp and therefore improve the operation?

Moxi

Funny you should mention that, as I've been pondering the same. In our case, we had our first 'failure' on Saturday, and had to buy day rate leccy from late evening. Poor weather, no real gen, and the washing was on. Same again Monday, but no washing, and batts exhausted an hour short of cheap rate. Yesterday was freezing, but the sunshine generation, meant we had 53% in the batts when cheap rate charging kicked in. Overall, looking very good.

So house temps OK, just hitting the edge cases. Not sure how unusual this weather is. The news keeps reporting the cold spell, but I was expecting temps like this (in Cardiff) for a few weeks, spread through the winter period, especially Jan/Feb. Is this unusual, or perhaps I was working to the more extremes as being average.

Could you not have plugged the car in when your batts were expended to get additional cheapslots?

Used the trick yeterday. Charged the Tesla on the 7kW charger but with Amps dialed down to 12A during the week, so Octopus learnt that it charges slow. Then yesterday, after poor gen, cold weather, and clothes washing / tumble dryer, the batts were running low, so plugged in the Tesla, and got a 9.30pm to 5.30am slot. Batts were at 1% at 9.30, then started charging them and running the A2A's, at cheap rate.

I love it when a plan comes together.

[Stinsy]

Funny you should mention that, as I've been pondering the same. In our case, we had our first 'failure' on Saturday, and had to buy day rate leccy from late evening. Poor weather, no real gen, and the washing was on. Same again Monday, but no washing, and batts exhausted an hour short of cheap rate. Yesterday was freezing, but the sunshine generation, meant we had 53% in the batts when cheap rate charging kicked in. Overall, looking very good.

So house temps OK, just hitting the edge cases. Not sure how unusual this weather is. The news keeps reporting the cold spell, but I was expecting temps like this (in Cardiff) for a few weeks, spread through the winter period, especially Jan/Feb. Is this unusual, or perhaps I was working to the more extremes as being average.

Could you not have plugged the car in when your batts were expended to get additional cheapslots?

Used the trick yeterday. Charged the Tesla on the 7kW charger but with Amps dialed down to 12A during the week, so Octopus learnt that it charges slow. Then yesterday, after poor gen, cold weather, and clothes washing / tumble dryer, the batts were running low, so plugged in the Tesla, and got a 9.30pm to 5.30am slot. Batts were at 1% at 9.30, then started charging them and running the A2A's, at cheap rate.

I love it when a plan comes together.

If you want to be extra cheeky you can unplug at 2302...