Heating season?

Air source, ground source and associated systems for heating homes
Mart
Posts: 1006
Joined: Mon Jun 14, 2021 1:17 pm

Re: Heating season?

#31

Post by Mart »

Anyone have thoughts on running the A2A at night using cheap(er) rate leccy?

PV for the next week will be poor, and drops fast anyway due to E/W panel orientation.

So, with temps at night rising to a more reasonable 8C to 12C, is it worth running the A2A, to reduce GCH? No plans to heat the house up, in fact, the one unit couldn't do that, but is warming at night a good idea, as losses may be a bit higher than letting the house cool, but balanced against a gas boiler .... OK?
3.58kWp ESE PV + 2.0kWp WNW PV.
Two BEV's.
Two small A2A heatpumps.
AGT
Posts: 654
Joined: Sat Jan 29, 2022 11:26 am

Re: Heating season?

#32

Post by AGT »

That was always going to be my plan run it on the night time tariff, get house to set temp in the 5.5 hrs cheap rate then top up as required..
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Stinsy
Posts: 2640
Joined: Wed Jun 02, 2021 1:09 pm

Re: Heating season?

#33

Post by Stinsy »

Mart wrote: Mon Oct 16, 2023 4:32 pm Anyone have thoughts on running the A2A at night using cheap(er) rate leccy?

PV for the next week will be poor, and drops fast anyway due to E/W panel orientation.

So, with temps at night rising to a more reasonable 8C to 12C, is it worth running the A2A, to reduce GCH? No plans to heat the house up, in fact, the one unit couldn't do that, but is warming at night a good idea, as losses may be a bit higher than letting the house cool, but balanced against a gas boiler .... OK?
A2A and ToU is super-cheap. I’m currently running a single A2A to heat my whole 5-bed house. Won’t last forever it can’t reach the far corners of the house. But it augments my GCH nicely and has convinced me that I only need a teeny 5/6kW ASHP.
12x 340W JA Solar panels (4.08kWp)
3x 380W JA Solar panels (1.14kWp)
5x 2.4kWh Pylontech batteries (12kWh)
LuxPower inverter/charger

(Artist formally known as ******, well it should be obvious enough to those for whom such things are important.)
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Joeboy
Posts: 7037
Joined: Mon May 31, 2021 4:22 pm
Location: Inverurie

Re: Heating season?

#34

Post by Joeboy »

Mart wrote: Mon Oct 16, 2023 4:32 pm Anyone have thoughts on running the A2A at night using cheap(er) rate leccy?

PV for the next week will be poor, and drops fast anyway due to E/W panel orientation.

So, with temps at night rising to a more reasonable 8C to 12C, is it worth running the A2A, to reduce GCH? No plans to heat the house up, in fact, the one unit couldn't do that, but is warming at night a good idea, as losses may be a bit higher than letting the house cool, but balanced against a gas boiler .... OK?
Mart, if you have a low overnight rate then it really is a no brainer to run the a2a with its 4+cop. I run mine in Turkey before I arrive for 2 days (Winter). It very quickly soaks the walls and ramps down. Concrete walls, I think you'll have significantly better thermal insulation?
16.2kW PV SE, VI & DW
Ripple 7kW WT & Gen to date 11MWh
28kWh LFPO4 storage
95kWh Heater storage
12kWh 210ltr HWT.
73kWh HI5
Deep insulation, air leak ct'd home
Zoned GCH & Hive 2
WBSx2
Low energy bulbs
Veg patches & fruit trees
Mart
Posts: 1006
Joined: Mon Jun 14, 2021 1:17 pm

Re: Heating season?

#35

Post by Mart »

Cheers guys.

OK, another silly thought (mine). Last night left it running on E7, but turned it down to 20C. During the day, if we have spare PV, then it runs at 25C if not using the room (lounge) with the door wide open, or about 22/23C if using the room, again with door partly open.

But, now I'm thinking I should have left it on higher, as it's not going to heat the whole house with lots of heat leaking outside, so better to have it work harder and spread the heat around.

Any thoughts?

Btw it's a 3.5kW unit, oversized for the approx 4m by 4m room, but deliberate to allow excess heat to escape and spread.
3.58kWp ESE PV + 2.0kWp WNW PV.
Two BEV's.
Two small A2A heatpumps.
AGT
Posts: 654
Joined: Sat Jan 29, 2022 11:26 am

Re: Heating season?

#36

Post by AGT »

I would set it to a temp it’s unlikely to achieve so it doesn’t cycle on/off.

Then it lets you see for x hours on, y power consumption
Etc
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Joeboy
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Location: Inverurie

Re: Heating season?

#37

Post by Joeboy »

Mart wrote: Tue Oct 17, 2023 8:04 am Cheers guys.

OK, another silly thought (mine). Last night left it running on E7, but turned it down to 20C. During the day, if we have spare PV, then it runs at 25C if not using the room (lounge) with the door wide open, or about 22/23C if using the room, again with door partly open.

But, now I'm thinking I should have left it on higher, as it's not going to heat the whole house with lots of heat leaking outside, so better to have it work harder and spread the heat around.

Any thoughts?

Btw it's a 3.5kW unit, oversized for the approx 4m by 4m room, but deliberate to allow excess heat to escape and spread.
Can you work the leaks?
16.2kW PV SE, VI & DW
Ripple 7kW WT & Gen to date 11MWh
28kWh LFPO4 storage
95kWh Heater storage
12kWh 210ltr HWT.
73kWh HI5
Deep insulation, air leak ct'd home
Zoned GCH & Hive 2
WBSx2
Low energy bulbs
Veg patches & fruit trees
Mart
Posts: 1006
Joined: Mon Jun 14, 2021 1:17 pm

Re: Heating season?

#38

Post by Mart »

Joeboy wrote: Tue Oct 17, 2023 8:13 am
Mart wrote: Tue Oct 17, 2023 8:04 am Cheers guys.

OK, another silly thought (mine). Last night left it running on E7, but turned it down to 20C. During the day, if we have spare PV, then it runs at 25C if not using the room (lounge) with the door wide open, or about 22/23C if using the room, again with door partly open.

But, now I'm thinking I should have left it on higher, as it's not going to heat the whole house with lots of heat leaking outside, so better to have it work harder and spread the heat around.

Any thoughts?

Btw it's a 3.5kW unit, oversized for the approx 4m by 4m room, but deliberate to allow excess heat to escape and spread.
Can you work the leaks?
Hopefully we're not too bad, but what I was thinking, but didn't explain (at all, sorry), was that the greater the heat differential between the inside and the outside, the more heat that will escape over time. I'm probably overthinking this bit, given it's a relatively small heat boost for the whole property.


Thanks AGT, that makes complete sense, my worries (paragraph above) seem silly, the more I think about it.
3.58kWp ESE PV + 2.0kWp WNW PV.
Two BEV's.
Two small A2A heatpumps.
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Joeboy
Posts: 7037
Joined: Mon May 31, 2021 4:22 pm
Location: Inverurie

Re: Heating season?

#39

Post by Joeboy »

Mart wrote: Tue Oct 17, 2023 8:51 am
Joeboy wrote: Tue Oct 17, 2023 8:13 am
Mart wrote: Tue Oct 17, 2023 8:04 am Cheers guys.

OK, another silly thought (mine). Last night left it running on E7, but turned it down to 20C. During the day, if we have spare PV, then it runs at 25C if not using the room (lounge) with the door wide open, or about 22/23C if using the room, again with door partly open.

But, now I'm thinking I should have left it on higher, as it's not going to heat the whole house with lots of heat leaking outside, so better to have it work harder and spread the heat around.

Any thoughts?

Btw it's a 3.5kW unit, oversized for the approx 4m by 4m room, but deliberate to allow excess heat to escape and spread.
Can you work the leaks?
Hopefully we're not too bad, but what I was thinking, but didn't explain (at all, sorry), was that the greater the heat differential between the inside and the outside, the more heat that will escape over time. I'm probably overthinking this bit, given it's a relatively small heat boost for the whole property.


Thanks AGT, that makes complete sense, my worries (paragraph above) seem silly, the more I think about it.
You should get cumulative effect. Max that bad boy out!

As to the heat differential, if you've done all you can to control leaks, don't worry.

I notice with No1's place that as its a small 2 storey maisonette the glass to air vol ratio is high. So the place heats well from solar gain. Same with the wee pv power panel heater. It makes a difference due to less air to heat and a massive loft cap of insulation.
16.2kW PV SE, VI & DW
Ripple 7kW WT & Gen to date 11MWh
28kWh LFPO4 storage
95kWh Heater storage
12kWh 210ltr HWT.
73kWh HI5
Deep insulation, air leak ct'd home
Zoned GCH & Hive 2
WBSx2
Low energy bulbs
Veg patches & fruit trees
User avatar
Stinsy
Posts: 2640
Joined: Wed Jun 02, 2021 1:09 pm

Re: Heating season?

#40

Post by Stinsy »

Mart wrote: Tue Oct 17, 2023 8:04 am Cheers guys.

OK, another silly thought (mine). Last night left it running on E7, but turned it down to 20C. During the day, if we have spare PV, then it runs at 25C if not using the room (lounge) with the door wide open, or about 22/23C if using the room, again with door partly open.

But, now I'm thinking I should have left it on higher, as it's not going to heat the whole house with lots of heat leaking outside, so better to have it work harder and spread the heat around.

Any thoughts?

Btw it's a 3.5kW unit, oversized for the approx 4m by 4m room, but deliberate to allow excess heat to escape and spread.
I wouldn't run the A2A all night personally. One of the key benefits of an A2A (particularly one oversized as yours is) is that they heat up a space very quickly. If I were you I'd leave the doors open overnight and have the A2A come on in the last hour of your E7 cheap period. Maybe have it running on it's lowest fan speed overnight if we get a REALLY cold spell.

BTW: what is your E7 tariff like? Most are terrible! I managed to get a friend's mum switched from 20p/kWh cheap rate on E7 to 5p/kWh on Octopus Go a few years ago (my friend took over managing her bills). My friend was worried about the shorter cheap period but the peak price on Octopus at the time was 15p/kWh!
12x 340W JA Solar panels (4.08kWp)
3x 380W JA Solar panels (1.14kWp)
5x 2.4kWh Pylontech batteries (12kWh)
LuxPower inverter/charger

(Artist formally known as ******, well it should be obvious enough to those for whom such things are important.)
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