UPDATED: Air Source Heat Pumps/Air Con - Full Info & Guide, is it cheaper to run than mains gas?

Diallingtone wrote: »

Hi all - I've joined MSE just so I can participate in this thread! I had an Ecodan installed back in August; an 8.5KW unit for my 3 bed house.

I was nervous - not least because of the heated debates elsewhere in these forums about ASHP efficiencies and associated horror stories. Reading all those posts from Cardew about how it was all doomed to failure

Anyway, I think my Ecodan is..... FANTASTIC!

Hot water has never been hotter - we are boosting via immersion much less, maybe 3 times in 6 months versus a few times per week before. Inside temp is absolutely fine, even when we've got down to -5º outside.

I've checked with the neighbours and they don't hear it - which was a concern - but to be honest it's less noisy than my rattly old LPG boiler. If you walk down our street at night, you can hear the heating going in most houses - mostly boilers venting outside. The Ecodan makes a different kind of noise, but in truth it's not any more intrusive.

The defrost cycle is amazing. Last night, I was looking at the unit and it's all frozen up - looks like the inside of a fridge. Then the unit makes a noise a bit like a lorry's air-brakes and, after a few moments, the ice turns clear and starts to run off as water into the soakaway.

I explain to people that it works by combining electricity with some clever gubbins and a pinch of pixie dust - no other rational explanation

ASHPs aren't perfect. Because the rads don't get as hot, it does take longer to get a house up to temperature - so we have the heating on all the time and keep it in a fairly narrow range; 16º overnight, 19º during the day and 21º at night. In my experience, it can take an hour to raise the temp by 1º - not a problem per se, you just have to plan a bit better.

I still can't comment on running costs. Back in August we were nearly £300 in credit with SSE and probably over paying by £20-30 per month. It will take a while to burn through that and assess increased payments. With Solar PV and Solar Thermal and no separate usage meter for the ASHP, I have no way of tracking what it uses with any confidence. No matter. I'm sure it's cheaper than LPG and every time I see that my LPG tank has gone, I still smile!

When the RHI payments kick in next year, I will hopefully get some dosh which will speed up the return on investment and be the proverbial cherry on the cake.

So far so good. Although I don't like the cold weather, I am secretly wanting the temperature to drop even further so I can see how well it works. Rated down to -15º, I think the coldest we've recorded round here is around -11º, so it should be interesting.
:beer: