Air source heat pumps - no thanks

[az city]

OK, don't shoot me but I have one.

To be fair, the house it's in is designed for it (18-inch-thick insulated walls, a heat recovery system, a small PV system, triple glazing and underfloor heating everywhere).

What I found at first was I couldn't get to grips with it and that it was totally frustrating. It took me a while to realize it won't work if you want instantaneous "on-demand" control. You have to leave it on almost all the time and draw from the slowly collected heat as you use the hot water and heating during your use of your house over a 24-hour cycle. Essentially, it's a system for people who are willing to plan.

It's actually very quiet. The house is cozily warm all the year and it's very cheap to run - my total electricity bill is less than 450GBP a year (I don't have gas).

[Gofer Blue]

OK, don't shoot me but I have one.

To be fair, the house it's in is designed for it (18-inch-thick insulated walls, a heat recovery system, a small PV system, triple glazing and underfloor heating everywhere).

What I found at first was I couldn't get to grips with it and that it was totally frustrating. It took me a while to realize it won't work if you want instantaneous "on-demand" control. You have to leave it on almost all the time and draw from the slowly collected heat as you use the hot water and heating during your use of your house over a 24-hour cycle. Essentially, it's a system for people who are willing to plan.

It's actually very quiet. The house is cozily warm all the year and it's very cheap to run - my total electricity bill is less than 450GBP a year (I don't have gas).

Wow, you have a fantastic set up there. MVHR + massive wall insulation + PV + TG + UFH...... ideal! Out of interest do you how many kWh you use p.a. per sq metre of house? There are very few houses in the U.K. that come anywhere near that kind of construction, hence ASHP not really viable for the majority.

Is it passive house (PH) standard? Not sure if they have PH over there though?

[az city]

Wow, you have a fantastic set up there. MVHR + massive wall insulation + PV + TG + UFH...... ideal! Out of interest do you how many kWh you use p.a. per sq metre of house? There are very few houses in the U.K. that come anywhere near that kind of construction, hence ASHP not really viable for the majority.

Is it passive house (PH) standard? Not sure if they have PH over there though?

For 2023, it used 1,316 kWh and has a footprint of 105m2. I think that qualifies.

I don't think the passive house standard is actually well specified though. I think a better standard would use space/building volume. (My house has cathedral ceilings.)

[Gofer Blue]

For 2023, it used 1,316 kWh and has a footprint of 105m2. I think that qualifies.

I don't think the passive house standard is actually well specified though. I think a better standard would use space/building volume. (My house has cathedral ceilings.)

From your figures I make it 12.5 kWh/sq.m., so yes, less than 15.0 = passivhaus! The electricity price is quite expensive there then: £450 for 1316 kWh is approx 35p per kWh but still £450 p.a. is still hugely different to the bill for an average house in the UK.

I hadn't thought much about volume as opposed to floor area (I'm just an enthusiastic amateur, not an engineer!). Does having high ceilings make a significant difference to heating costs?