Air to air heat pump : Any regrets?

Parkhall

The air to air heat pump concept is appealing to me as I live in an old stone walled home and the sheer upheaval of air to water doesn't seem worth it at my age.

Can I ask some simple questions to those who have installed air to air? Do you have any regrets about it? Was it successful?

Newbie_John

No regrets, fully successful here :)

I've installed mine November last year and survived winter with so much comfort and heating costs dropped by 2/3 (compared to normal electric heaters we had before).

I've put some more details here:

https://forums.moneysavingexpert.com/discussion/6574532/air-to-air-heat-pump

Only issues I can think of is picking the right tarrif - the Heat Pump alike are not that good - yes you get cheaper periods but you also get more expensive ones and balancing it with device that's best to run constantly is tricky. I'm on Cosy tarrif and with my winter settings trying to make most during cheap periods like 4-7am. And at that 4am when it goes on a full swing you can hear the outdoor unit in the bedroom that's sharing the wall - quietly maybe like fridge, but noticeable.

Some other things I've learnt after is that it comes with "drying/dehumidifying" setting but that only works when cooling :)

These are the only downsides I can think of, all in all compared to savings they're totally negligible. I would happily recommend to everyone.

/Water heating (or it's lack) also is something to keep on mind, with have old solar thermal so A2A was perfect.

zxzxzx

The only downside I have found is that whilst it warms the house air it cools quickly when switched off. I use it in shoulder months so have not run it 24/7.

Jemma01

Mine came with the house, purpose-built, the EPC rating is C, the house is very well insulated. What's your insulation like? I maintain my house at 21 degrees, so I won't say it's a cheap option for my use. Do I regret buying a house with a heat pump? Honestly, no. I feel indifferent about it. Would I have invested money to get it? Also, no. Partly because I didn't have anything to compare it to. I find my bills very high, the highest I've ever seen them. But then I never control this one, I just set the temperature and accept the bills.

silverwhistle

Good question Parkhall as I'm also looking in to it. With a mid terrace house which is reasonably well insulated I think I can get away with single unit downstairs and a fairly low rated one at that being in the coastal south and have a wood burner for cold and miserable days. Water heating is from PV and a diverter in addition to gas, there's an upstairs electric towel rail and I'm an adept user of Agile alongside my PV.

This last winter when Agile was negative or cheaper than gas I experimented with direct acting electric space heating to see what rating I might need, hence my belief in getting a low rated unit.

I find that a lot of people prefer a lot higher temperature than myself and throughout the house to boot but as my gas bill was less than 2200kWh last year my ultimate aim is to get rid of gas entirely and save nearly £100 a year.

FreeBear

This last winter when Agile was negative or cheaper than gas I experimented with direct acting electric space heating to see what rating I might need, hence my belief in getting a low rated unit.

I've been running my central heating system with a heat meter attached to the flow/return pipes. Not had many days when it was sub-zero, and just one day when it dropped to -6°C. Boiler output peaked at 6.9kW and indicated an hourly rate of 5kWh. I think I also benefited from a bit of solar gain that day as the temperature was at 20.4°C at lunchtime (boiler had shut down around 10:00).

Based on that data, I'm leaning towards a heat pump rated at 8kW as sufficient to heat this old 1920s 3 bed semi. From some of the other tests I ran, at around freezing outside, a boiler output of around 3.5-4kW is sufficient to maintain the temperature at a comfortable level.

Admittedly, having a heat meter and logging the data continuously is probably a lot more than most would want to do. But the equipment isn't that expensive, and it does provide some valuable information for when the day comes. In the meantime, I get to play with settings to improve efficiency. Currently getting 92-94% out of the boiler which is much better than the SAP winter rating of 88.5%.

In the absence of complex monitoring systems, a couple of electric fan heaters plugged in to Tapo smart plugs (other makes available) is a reasonable method to guage heat loss. I did a similar exercise after insulating the walls of a box room.