I've recently attached a Shelly Power Meter to my A2A. Here is a cycle from yesterday:
The weather is highly changeable at the moment, we've had -6℃ at midnight one day and 12℃ the next, this has made scheduling the various heater challenging. Currently the A2A is set to run from 0600-0800 in the mornings (and the oil-filled in the kitchen is on the same schedule). We then manually turn on the A2A (well by asking "Alexa") if we feel cold in the afternoon and turn it off when we go to bed, it has a 21℃ target temperature. In cold weather we leave it on all day. I game an 0530-0900 additional cheapslot every day.
It looks as if there was defrost cycle at 1730ish.
Frustratingly there is no way to measure heat output. But our bills for heating a 5-bed house really do speak for themself...
Re: A2A Consumption
Posted: Thu Dec 05, 2024 10:42 am
by Stan
Interesting to see the size of your defrost cycle.
We had a Toshiba Haori A2A mini split installed a month ago and I write down data as best I can including what else was on that day.
This is one of those cottages where the rooms are all in a line, downstairs and upstairs. The most pleasing result is that the warmed air circulates from the room with the inside unit through a 30inch doorway to kitchen and diner with the fan on lowest (noiseless) speed, keeping all at 19C. The unit is on 24hrs and we shut those rooms not in use. At bedtime I open that door and a wad of warm air flows upstairs and in.
I only light the log burner on evenings when temps are down to say 3C. This must have halved log use.
When I calculate the average usage for this month against last november we only seem to have used 3kWh more per day but as you said November 2023 was a lot colder than this November.
The point is that it has made the cottage much more comfortable and the electricity use is small. It was installed in a day.
Re: A2A Consumption
Posted: Thu Dec 05, 2024 10:48 am
by Stan
This is a typical installation.
Re: A2A Consumption
Posted: Thu Dec 05, 2024 11:04 am
by SporranMcDonald
Good results here too from my (2nd) A2A Heatpump.
It's a 4kW dual-split unit feeding into the two coldest rooms on the north side of the bungalow. . . . and effectively warming the whole house.
It chugs away at around 240 Watts most of the time.
* I have hardly used the 5kW (other) unit so far this winter.
** No log-burning at all. The stove is on standby for emergency use only.
Re: A2A Consumption
Posted: Thu Dec 05, 2024 11:35 am
by Stinsy
I've said it lots of times on here, but I'm happy to repeat: My poorly located, oversized, A2A does an amazing job at heating my whole 5-bed house. It is augmented with a few resistive heaters (eg kitchen and livingroom downstairs). While it isn't possible to get perfect efficiency measurements, and this new power monitor is an attempt to better understand how much power the A2A consumes, comfort levels are high and bills are low, whatmorecanisay?
Re: A2A Consumption
Posted: Thu Dec 05, 2024 12:13 pm
by spread-tee
Exactly same as that, one unit on the first floor can cool the bedrooms and ground floor in the summer, and heat the bedrooms and loft rooms in the shoulder months with a bit of help from the ground floor UFH. If I were doing it again I would put two units in, one at the top and one at the bottom, but when this went in it was with an eye to keeping Mrs Desps mum happy who had most of the first floor.
Desp
Re: A2A Consumption
Posted: Thu Dec 05, 2024 12:25 pm
by Mart
Working well here too. In fact it dawned on me last week to work one unit harder at night. So when I go to bed, I turn it up 2C instead of 1C now, and dial the fan into the kitchen up to notch 2 (of 3). That had a big impact, raising kitchen temp about another degree, with hopefully even more heat escaping into the hall, and then up through the house.
In the morning, I then dial the unit (and fan, it's a bit noisy) down again. But seems to be a good way to maximise cheap rate leccy.
Re: A2A Consumption
Posted: Thu Dec 05, 2024 1:59 pm
by nowty
Mart wrote: ↑Thu Dec 05, 2024 12:25 pm
Working well here too. In fact it dawned on me last week to work one unit harder at night. So when I go to bed, I turn it up 2C instead of 1C now, and dial the fan into the kitchen up to notch 2 (of 3). That had a big impact, raising kitchen temp about another degree, with hopefully even more heat escaping into the hall, and then up through the house.
In the morning, I then dial the unit (and fan, it's a bit noisy) down again. But seems to be a good way to maximise cheap rate leccy.
This is something I've never really done, but sounds a good idea, I'm going to try this on my downstairs unit by leaving it on 24/7, it should save the radical heat up sourced from my batteries in the morning.
Mart wrote: ↑Thu Dec 05, 2024 12:25 pm
Working well here too. In fact it dawned on me last week to work one unit harder at night. So when I go to bed, I turn it up 2C instead of 1C now, and dial the fan into the kitchen up to notch 2 (of 3). That had a big impact, raising kitchen temp about another degree, with hopefully even more heat escaping into the hall, and then up through the house.
In the morning, I then dial the unit (and fan, it's a bit noisy) down again. But seems to be a good way to maximise cheap rate leccy.
This is something I've never really done, but sounds a good idea, I'm going to try this on my downstairs unit by leaving it on 24/7, it should save the radical heat up sourced from my batteries in the morning.
Yep, or as others suggested to me, at least for the last couple of hours of cheap rate, to get the temp up, and the compression(?) etc. etc. to reduce load in the morning.
Still can't believe how well the fan is working. I'm no longer pondering an element for the radiator, as the room is now fine, when I expected it to be a problem area.