Air sourced heat pumps

I've just been speaking to a plumber about these pumps. He says that there is a big push on to get them installed, but that except for new builds, most houses would need a lot of extra work in bigger radiators, new pipework (bigger than microbore) and extra insulation. He didn't think it would be suitable even for our house, which is 15 years old and well-insulated with underfloor heating but in a cold area.

Apparently the trade is trying to get movement from the government on bringing hydrogen into the mix in current gas pipes, which would allow current boilers and other gas appliances to be used with a bit of tweaking (remember when gas changed from coal gas to natural gas?) and would therefore be a lot cheaper. New boilers are now being made hydrogen-ready. That sounds good to me! Why do I find myself wondering which Tory party donor is making air source pumps...

We looked at this very carefully when planning our build, 11 years ago. We took advice from the Energy Saving Trust and the Centre for Alternative Technology. Their advice was that, from a carbon efficiency point of view, the co-efficient of efficiency must be 4 or above - that means that for every unit of electricity used to run the pump, you must get the equivalent of 4 units out. At the time, some manufacturers were claiming 3-4, but trials showed much less.
I have kept an eye on this, and the advice is less clear now. I am aware that Mitsubishi are claiming a co-efficient of 5, but have seen no independent proof. I am also aware that now we get more electricity from renewables, the calculation may be different. I would seek personal advice from those bodies if I needed a new boiler.
The 'greenest' way to heat a house it to insulate, insulate, insulate, and use solar thermal power for hot water - this also heats our underfloor heating. We also find our mechanical heat recovery pump very useful - it circulates & re-distributes warm air around the house. These are really only suitable for new builds or major conversions / renovations as you need to run pipes round the house.

I remain wary of the claims of air pump sales teams. I also think that the government needs to put money into making sure that new builds have all of these facilities.

Surely the simplest and cheapest solution is to replace a gas boiler with an electric boiler. Yes, they are expensive to run, but if we go all electric, or should I say when we go all electric, then any form of heating will be much more expensive.

Heat pumps, as Germanshepherdsmum need to be in houses with fully insulated floors and underfloor heating. For a large part of the housing stock both these requirements are unfeasable. Fancy having every floor in the ground floor of your house dug up, foundations excavated and insulation and a cement screed laid?

We have just built a Kitchen extension, the extension was dug out several feet to put in floor insulation then screed. We considered having the existing kitchen floor removed and fully insulated. then we looked at what it would involve, pneumatic drills to break up the current floor slab, removing the rubble and then laying a new floor: insulation and screed. Then we looked at the cost of doing this, in one room and we rapidly changed our mind. Imagine doing that for the whole of the groundfloor of a house, it doesn't bear thinking of. The cost could be £10,000 or more, plus new radiators and the heat pump.

When we transfer it will be either a straight boiler swap, electricity for gas or we will put electric heaters in each room all wired in to a central computer control system that can turn heating on and off in each room as needed with every rooms temperature controlled by a room by room thermostat. That might be cheaper to run than an electric boiler and would certainly be less disruptive.

Our home was converted from a 60s bungalow into a contemporary house about 6 years ago. We have a Mitsubishi air source heat pump, serviced once a year, which was installed as part of the conversion and keeps us very cosy despite having very large areas of glass in several rooms. We don’t need to use any secondary form of heating. We’re all electric and feel the bills are reasonable. However we have underfloor heating throughout and lots of insulation. Also we live in East Anglia. I’ve heard that they are not efficient enough in colder areas and if you attach them to an existing radiator system larger radiators may be needed. Ours isn’t noisy btw.

JaneJudge

We wondered if solar panels would have helped moorland

I felt the solar panels were excellent and were what kept the electricity bill down. The woodburner was cosy and, combined with the great insulation in the house one evening's fire would heat the whole (small three bed) house and keep it warm for a few days.

The air sourced heat pump appeared to me to be ineffective and seemed to put all its energy into just making a damned noise.

We wondered if solar panels would have helped moorland

I lived on a new estate where the Housing Association houses were all built with air sourced heat pumps. When that was insufficient the supply automatically switched to mains electricity.

It was a disaster. Some families had winter bills of over £2000 and many switched off their heating systems altogether.

In the third year all the houses were converted to gas boilers.

I had one in a house I rented. It was a new, eco-designed house which had the heat pump, solar panels and a woodburner. Between the three of them I paid zero electricity bill as they had it covered.

That said, I could not sleep as the air sourced heat pump 'unit' outside my bedroom window was so noisy - an almost constant, droning whirr. I would not have one again.

Yep, I have it. Electric bill is 20 pounds a month. Was colder in winter though. Needed extra fires

JenniferEccles we were without a boiler in last winter’s cold snap. It decided that it had reached the end of its life, at 25 years of age! We really struggled with temperatures as low as minus 17deg at night and some days not rising above minus eleven.

We spent a small fortune on coal & wood for a fire, electric heaters in other rooms and heating the kettle for hot water. We were lucky enough to be able to afford even this ineffectual solution but it’s a concern how less well off people would afford it in times of very low temperatures.

I was reading a piece about this a few days ago and the general impression was not favourable at all.

Apparently they are useless in temperatures below 10 degrees.

I am pretty sure the government will have to have a rethink on this.

I’ve not heard much good about them, particularly for areas such as I live in, NE Scotland, where it can get very cold. As well as the issues others have mentioned, your house needs to be very well insulated for it to work properly. That’ll be an issue for older properties built of stone etc.

Apparently it costs £10,000 ?

I looked into this a couple of years ago and took my info from Canada where they have years of experience.
Here's a link to a Canadian government website which is (in my opinion) very interesting:
www.nrcan.gc.ca/energy-efficiency/energy-star-canada/about/energy-star-announcements/publications/heating-and-cooling-heat-pump/6817

I also watched a number of videos explaining the pros and cons and was particularly interested in the ones from Canada for the same reason.

I was looking at a new-build that had one and was sceptical. I feel much more positive now and would definitely look at this for a new-build.

sorry - in winter of course!

My friends in France have one of these - it heats house in winter and cools in summer. It is a unit about half the size of a fridge that is fixed to an outside wall.
Also friends in the village have a ground source heat pump. It involved large excavations in their garden.

Both do not heat the house sufficiently in summer - but if we are going to have global warming then maybe that would not matter so much. But I doubt the global warming is actually going to raise the ambient temperature much, but simply mess with the weather and the polar ice caps.

It once broke down and it had to be referred to three different people/companies. In the end an older gentleman arrived with an inspector gadget van and made a tool on the drive 'to fix it'
He made a tool to fix it!
He was like the professor out of despicable me

Oh dear it’s not sounding good at all no positives here.

My experience is you have to have another source of heat in winter. We used to have light the fire in the lounge and spend most of our time in there. Of course they are banning coal/logs too aren't they

We live rural with no gas supply and had one we moved here. It used to break down constantly and no one knew how to fix it. It never really generated enough energy to heat both the water and the heating. Bath's had to be well timed, especially in the winter. It was an expensive system too. Last winter it quite literally 'blew up' causing catastrophic damage to the thing that sat outside (sure there is a technical name but it escapes me) So we swapped to an oil system.

Honestly, I have nothing good to say about it. It took up loads of space as well.

Ridiculous really. Not many will be able to afford it and the end result is that we will still be cold.

I’m another who is interested in this, and also I’m quite concerned about what I’m hearing. Extremely expensive (so how are poorer people going to afford it) and not terribly good at heating the house. I like my warmth in the winter as I’m always cold, so I won’t be happy to pay thousands of pounds (10 thousand for the pump has been mooted) and the end result is that I’m cold!

Very interested in this too although I’ve been looking at ground source heat pumps.