Discussion ... ASHP(Air/Air) with Solar pv ....
Comments
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January 2017 update for using the Toshiba Air Conditioner/Heat Pump.
Comparing Gas & Electric use from January last year have ended up with the following figures:
Gas use down by 1489 kWh
Electric import up by 64 kWh
Therefore, since Toshiba Unit was installed mid November 2016, total difference:
Gas use down by 2227 kWh @ 2.3486p/kWh = £52.30 less
Electric import up by 155 kWh @ 10.815p/kWh = £16.76 extra0 -
ASavvyBuyer wrote: »January 2017 update for using the Toshiba Air Conditioner/Heat Pump.
Comparing Gas & Electric use from January last year have ended up with the following figures:
Gas use down by 1489 kWh
Electric import up by 64 kWh
Therefore, since Toshiba Unit was installed mid November 2016, total difference:
Gas use down by 2227 kWh @ 2.3486p/kWh = £52.30 less
Electric import up by 155 kWh @ 10.815p/kWh = £16.76 extra
Interesting, however what do you deduce from these figures, and those in previous posts?
Without data about weather at your location for the comparison months, and any lifestyle changes, you cannot come to any conclusion about the efficiency(COP) of the heat pump.
Certainly the heat pump itself cannot have reduced gas demand by 1489kWh for an additional import of 64kWh electricity.
P.S.
I have read the previous posts.0 -
Certainly the heat pump itself cannot have reduced gas demand by 1489kWh for an additional import of 64kWh electricity.
There's a clue in the thread title. Also, if you read the previous posts you'll see that part of the idea is to maintain warmth in the room you are using and avoid heating all of the property.Mart. Cardiff. 5.58 kWp PV systems (3.58 ESE & 2.0 WNW)
For general PV advice please see the PV FAQ thread on the Green & Ethical Board.0 -
HiMartyn1981 wrote: »There's a clue in the thread title. Also, if you read the previous posts you'll see that part of the idea is to maintain warmth in the room you are using and avoid heating all of the property.
That post hits the nail on the head ... January pv generation here was comparatively poor and the heat-pump was used every day but our electricity import for January 2017 was 37kWh higher than Jan2016 and 15kWh higher than Jan2015 ... currently running the house+heat-pump (approx 2.5kW.t) with 55W of import ....
HTH
Z"We are what we repeatedly do, excellence then is not an act, but a habit. " ...... Aristotle
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Hi
That post hits the nail on the head ... January pv generation here was comparatively poor and the heat-pump was used every day but our electricity import for January 2017 was 37kWh higher than Jan2016 and 15kWh higher than Jan2015 ... currently running the house+heat-pump (approx 2.5kW.t) with 55W of import ....
HTH
Z
I'm jealous.
What do you think of this plan.
We are getting the conservatory renovated in a month. It's not really a conservatory, just a 2.5m cube. Two walls are .... walls, number three is half wood, half DG linked to living room. The last wall is UPVC and glass (doors and windows). The roof is polycarb, but we are changing to DG.
The plan is to fit black out blinds on the roof and windows.
Today both the conservatory and garage started at about 10C. The garage is on the NNE wall, no direct sun at this time of year and has crept up to 11C, but the conservatory got to 15C. That suggests to me that it wouldn't take much effort to warm it up, open the door, and heat the living room. And the opposite in the summer, if the blinds keep the heat out, as the sun starts to move off it by 2pm, when cooling may start to be needed.
So, the plan is to pop the ASHP in the conservatory, and use it that way, as we can't find a way to run it 'nicely' to the living room which doesn't have any exterior walls.
Would I be wasting PV export to warm/cool the conservatory by fighting with nature, as it's unheated?
Naturally, the days when I'll have excess to heat, will be the days that the sun will be warming it up too.
Hard to explain this, but opening the door to the conservatory, makes the living room feel much nicer, and helps to bring the garden indoors (can't explain what I mean).
Is this a bad, average or good plan?Mart. Cardiff. 5.58 kWp PV systems (3.58 ESE & 2.0 WNW)
For general PV advice please see the PV FAQ thread on the Green & Ethical Board.0 -
HiMartyn1981 wrote: »I'm jealous.
What do you think of this plan.
We are getting the conservatory renovated in a month. It's not really a conservatory, just a 2.5m cube. Two walls are .... walls, number three is half wood, half DG linked to living room. The last wall is UPVC and glass (doors and windows). The roof is polycarb, but we are changing to DG.
The plan is to fit black out blinds on the roof and windows.
Today both the conservatory and garage started at about 10C. The garage is on the NNE wall, no direct sun at this time of year and has crept up to 11C, but the conservatory got to 15C. That suggests to me that it wouldn't take much effort to warm it up, open the door, and heat the living room. And the opposite in the summer, if the blinds keep the heat out, as the sun starts to move off it by 2pm, when cooling may start to be needed.
So, the plan is to pop the ASHP in the conservatory, and use it that way, as we can't find a way to run it 'nicely' to the living room which doesn't have any exterior walls.
Would I be wasting PV export to warm/cool the conservatory by fighting with nature, as it's unheated?
Naturally, the days when I'll have excess to heat, will be the days that the sun will be warming it up too.
Hard to explain this, but opening the door to the conservatory, makes the living room feel much nicer, and helps to bring the garden indoors (can't explain what I mean).
Is this a bad, average or good plan?
The way I see it is that if you want to heat the house then the indoor unit needs to be in the house else you're simply wasting generation/heat ....
If you're going to be working on the conservatory anyway, is it possible to run the pipes along the conservatory (internal) walls (in trunking) and link the outdoor unit through to a unit in the lounge that way ?? ... a couple of metres of pipe run isn't likely to have as much effect on overall heating efficiency as heating an 'outdoor glass box' ...
HTH
Z"We are what we repeatedly do, excellence then is not an act, but a habit. " ...... Aristotle0 -
Martyn1981 wrote: »There's a clue in the thread title. Also, if you read the previous posts you'll see that part of the idea is to maintain warmth in the room you are using and avoid heating all of the property.
That is very much the point. Most of the time when the heat pump is on, from the monitor on it's consumption, it is only drawing between 100 & 200 watts, except for when it first turns on in the morning or if we boost it up for a short time. Most, if not all of that power is coming from spare PV generation. This is instead of the oil filled radiator, we used last winter, that needed at least 500 watts of spare generation before the circuit to it would get switched on.
Also, as mentioned before, we are tending to spend more time in the lounge, where the heat is and reduce heating in other rooms, except when they are in use.
From checking the historical records at Accuweather.com for weather in Jan 2016 & Jan 2017, in fact this Jan has been slighlty colder with 5 days at freezing or below, compared with only 2 last year and most other days last Jan being a degree or 2 warmer.
One of the mains things that appears to have saved the most gas is not needing to put the gas fire on. Have not used it once since the heat pump was installed as the room is already warm.
Only other change has been putting a new larger central heating radiator in the bedroom (which warms it up very quickly when needed) controlled by a programmable TRV, as the old one under the window is coming out so that french doors can be installed sometime this year.0 -
February 2017 update for using the Toshiba Air Conditioner/Heat Pump.
Comparing Gas & Electric use from February last year have ended up with the following figures:
Gas use down by 1355 kWh (a saving of just over 59% compared to last year)
Electric import up by 26 kWh (an increase of just over 13% compared to last year)
Feb, a day shorter than last year. From checking the historical records at Accuweather.com for weather, it has also been slightly warmer, most days, with only 4 days freezing or below compared with twice that many last February. Solar generation in February also poorer than last year, with a lot of overcast days.0 -
Hi
Just to suppliment ASavvyBuyer's post above ..... worst Feb so far for PV generation here, down by ~65kWh on last year, so importing 21kWh more electricity than the same month last year despite adding the heat-pump probably doesn't look too bad at all considering that it's usually been on from mid/late morning through to late evening throughout the month.
HTH
Z"We are what we repeatedly do, excellence then is not an act, but a habit. " ...... Aristotle0 -
March 2017 update for using the Toshiba Air Conditioner/Heat Pump.
Comparing Gas & Electric use from March last year have ended up with the following figures:
Gas use down by 882 kWh (a saving of 56% compared to last year)
Electric import up by 34 kWh (an increase of just over 22% compared to last year)
From checking the historical records at Accuweather.com for weather, it has been very similar to last year, temperature wise, but with a lot more grey, overcast days. Therefore, solar generation in March again poorer than last year. Other difference, were away for a week in March last year.0
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