Using the AC to provide more direct targeted heating, possibly lowering my expenditure

Martyn1981

It works, so to speak for us, though admittedly most of the leccy used during the day now is imported. We have a 3.5kW unit running, so it's drawing about 700W, and the economics of leccy prices v's gas prices may seem questionable for that one room/area, but like the OP, we're able to heat the room/rooms that are mostly in use, so that means that we don't have to heat all of the house, all day ...... though this will undoubtedly change as we get into Jan/Feb and the really cold temps arrive.

In the shoulder months, or at least most of the days, we're able to heat just from the AC's, and mostly from PV, especially if a coldish house in the early morning is acceptable before generation rises, and we do benefit from good early PV generation (Mch to Oct) with east facing PV.

mickyduck55

QrizB said:

jimjames said:

Will it actually work though at this time of year?

There are other threads where MSErs (Martyn for one) have stated that it works in the "shoulder months" of spring and autumn. The AAHP will run at a few hundred watts input, producing 4x that as output heat.

I don't think Mickyduck55 is expecting his solar to supply the power, but to buy electricity for this. The saving he's looking to make comes from heating the rest of the house less and so buying less gas, combined with the decent COP that AAHPs offer.

Correct I can buy my electricity for reasonable unit cost and store it in my batteries.. solar is a bonus,  today panels have generated 8.3 kWh
My gas expenditure today so far is about 50p... low because I have made a "Sunday Roast and baked".. heat from the electric oven warming the kitchen and to some extent the hallway.

jimjames the AC seems to draw 0.7kWh.... that is using the unit in the living room.

Living room is at 20 C..... AC set to 18 C.   I do believe this will work for me

mickyduck55

Signed up for "Octopus Winter Workout", that should give me some indication as to how this works over a 12 week period.

michaels

QrizB said:

jimjames said:

Will it actually work though at this time of year?

There are other threads where MSErs (Martyn for one) have stated that it works in the "shoulder months" of spring and autumn. The AAHP will run at a few hundred watts input, producing 4x that as output heat.

I don't think Mickyduck55 is expecting his solar to supply the power, but to buy electricity for this. The saving he's looking to make comes from heating the rest of the house less and so buying less gas, combined with the decent COP that AAHPs offer.

The other thing about 'shoulder months' or even days is that the higher the outside temp the better the cop, so for example using the AAHP rather than the gas may be cheaper full stop (before considering only heating certain areas) down to perhaps 8 degree outside temp if that is the temp at which the cop falls below 4.  Because the units are in place for AC the capital cost can be ignored in the calcs.

mickyduck55

I can only heat my bedroom and lounge as they have the units installed. 

Bedroom is never heated as I sleep with the window open all year round.. central heating is set to 15C because of the location of the sensor in my hallway by the time this temp is reached my bathroom is comfortably warm... this may not be comfortable for all of you but I'm from't North

The AC in the living room is switched on at about lunchtime and set to 18C with the temp cycling from 17-21.. this is plenty warm enough for me and I do often turn it down if the gas CH is also running.  The AC does overheat the room then turns off until the room cools again.  An added feature is that as the units are accessible via the internet If I'm out I can turn then on remotely 30 mins before I get home.

ATM all is good we have had some very cold but sunny days in January and I am still purchasing almost all of my electricity at the "go" rate of 5.5p.. so this does work for me.  If I was not on "go" then the situation would be more difficult to justify.

As stated above I bought the units to use in the summer to cool when I have plenty of excess solar rather than heat so this for me is an added bonus that I had not considered when I purchased my split system