Using air conditioners as air source heat pumps

anon_ymous

I appreciate this is nearly a year later, but was just wondering if people have managed to get a decent COP from just air conditioning used as heaters? Even if you've got a leaky house? 

Do you have a whole house set up too? 

Mikeyboy01443

I have a daikin system with 4 indoor units which i use to heat / cool the whole house,  kind of. 
1 in the lounge, 1 in 2 of the 4 bedrooms upstairs, and one in the conservatory. 
If i want to heat the house up i just open the bedroom doors upstairs and run them and the lounge unit, seems to work quite well.
The kitchen gets cold but i take the approach of only heating rooms where people are, seems pointless heating the whole house if we are all in the lounge...
I very rarely use gas and use the cheap overnight rate to heat up a bit to stop the gch coming on as others have said.
First time I have seen it struggle a bit is the last week where it has been very cold but it has still heated up OK, just not as powerful perhaps.
The daikin system is great as you can set schedules easily, not sure how the other systems compare for that kind of thing. 
The only downside for me really is it eats my battery storage quite quickly if I'm running them!

1961Nick

I've just come off a Go contract @ 13p peak & moved onto Intelligent @ 40p peak so I'm having to be more circumspect about running the ASHP. I can spare about 3kWh from the batteries for daytime use & still get through to 23.30 but it's a balancing act with the low temperature significantly reducing the COP.

Shortsy

I've been reading this thread with interest as I'm considering putting in at least one air to air pump to boost heating and provide cooling on the ground floor, but the dilemma is what to do about other floors (we have a narrow 4 storey end terrace townhouse with it's loft converted). I was intending to go for a multi split, maybe with 3 units across 3 of the 4 floors, but then learnt that they are less efficient than individual units! We have six habitable rooms so a full system would be a sizeable investment and duplicate our combi/ radiators, and wouldn't give us a hot water solution. Also if we add a second outdoor unit after trying the first one we need to get planning permission!

ispookie666

@Shortsy
With a longish house, maybe better to go with individual units. These are very good for cooling and heating. With multi split, you would be only able to have all the indoor units on the same mode. This would not have worked for us as one of the bedrooms is cooler and needs heating when other rooms needs cooling. The units which can work in different modes are considerably expensive. 

 Irrespective of the number you will need PP approval for each unit. Larger units might necessitate noise assessment for PP. 

Shortsy

@ispookie666, thanks for your advice. For our house, I can't imagine that we would need cooling and heating modes at the same time, but it's the reported drop in efficiency that concerns me.
The units would face a foot/cycle path with trees and a retail park service yard beyond, so I am not expecting to be asked to do a noise assessment (nor would I be willing to pay for one).
The house isn't particularly long, it's about 40 sqm per floor (about 8m x 5m). It gets tricky to design units for higher floors as there are three bedrooms with no direct access to the gable wall due to fitted cupboards or an ensuite. I was wondering if one more unit was fitted to the loft room on the 4th floor whether it could condition the floor below with the door open down the stairs; or even putting one in the second floor stairwell and opening the bedroom doors either side to condition those from the landing.

Coastalwatch

Living in a bungalow I'm hardly best placed to offer any advice, however we do have two individual units which are ideal for our purposes. I have a friend who has a single unit downstairs which heats this area and upstairs very well. But when it comes to cooling in the summer then only downstairs gets cooled with the first floor being unbearable at times last summer. Can only suggest from his experience that units for heating are placed in the lower floors with and an additional unit in the loft to take care of cooling for lower floors. From our data then for every kWh used for cooling, ten have been required for heating.