UK homes install subsidised heat pumps at record level | Hacker News Reader

UK homes install subsidised heat pumps at record level

bbc.co.uk

23 pointsRobinL23 comments

I had mine installed last year through the Scottish scheme. Thoughts so far:

- system works fine and maintains a nice even temperature, despite undersize 8mm radiator piping. More comfortable than the legacy gas system which was often too hot

- mine is actually a hybrid (with gas boiler for HW and very low temperatures). This was a compromise that several installers pushed for due to the undersize piping

- did not have to replace radiators (phew) or piping (absolutely not willing to do that)

- installers generally seem very new to this; completion delayed by a day as they had to bring someone else back who knew how to program it. Also too much exposed (well, thinly insulated) pipework outside the building

- overall cost is still high even if the government is subsidizing it, I suspect something is not right here

- decision of the subsidy scheme to not subsidize bidirectional AC distorts the market somewhat. I know it's not traditional in UK homes but the south of England may start wanting AC and air/air may be easier to plumb in some cases

- noise: nonzero but not an issue, just about audible at night indoors. If you're next to a road then it will be much quieter than the background noise.

- running cost: not significantly cheaper than old gas system, because electricity is still very expensive

Does the Scottish scheme allows for gas to be kept? In England the gas boiler has to be removed and you won’t be able to reinstall it later.

No such requirement to remove gas; the grant won't fund the boiler part of a hybrid system, but it doesn't preclude having it.

I did consider it but all the installers said I'd have to upgrade the piping (i.e. rip out every floor in the house)

Ok, sadly in England the installer has to disconnect and remove the gas boiler and you won’t be able to reinstall it afterward as your property becomes blacklisted for such installations by the utility providers.

British Gas basically won’t touch you. You can keep gas for cooking I think still but the boiler has to go.

Do you mind sharing some numbers? Looks like it’s a £7,500 grant with a matching loan? What is your monthly heating bill now? Do you think a battery + octopus 7p deal would bring down the costs?

Yes, that's the available money. It ended up being closer to £10k and I paid the balance rather than deal with a loan. Monthly bill is £200 for everything (including gas HW and hob).

I would probably benefit from a smart meter + time of use tariff. I need to research whether that would impact my existing solar FIT arrangement.

I'm definitely coming round on the idea of a heat pump. My house was built in 2002 and still has the original gas boiler that was installed from then. I'm hopeful that I have enough insulation, but I've been told I may have microbore piping which might need to be upgraded. Not done much more research on it than that.

Also apparently my gas boiler has an air brick that's too close to the output for the boiler on the outside of the house, so they'd have to install a bigger flue that goes halfway up the house.

From what I've heard the installation cost (even with £10k subsidy) will still be minimum £5k compared to a new gas boiler of £2.5-3k.

After everything that's happened with the gas prices in the past 3 years, I'm very eager to remove that dependency from my house. Now we just need to decouple the gas prices from the renewable energy prices so we can start to see those lower prices to the home. One can dream.

Disclaimer: I've never been to the UK outside of Heathrow, but my impression is that climate wise it would be ideal for heat pumps. Cold, but not like COLD COLD. OK Google says 0F for the record low in London, compared to -15F in NY City.

Climate wise: yes.

Housing stock wise: not so much.

Heat pumps seem really good for well insulated modern houses, much of the UK's housing stock is >100years old and pretty drafty.

Agreed that homes can be better insulated. However, poorly insulated homes still need heat. Heat pumps seem like a good step despite poor insulation.

I hear this a lot. I've got quite a leaky 400+ year old Welsh farmhouse (long and thin, heat-sucking 4ft deep stone walls) and I'm one of those who installed last year with the grant.

It's bloody brilliant. Way, way more comfortable than the oil-fired system it replaced. The smart meter looked a bit scary during the cold patch in January but even then, it's coming in cheaper than the oil did and without the scary price variability.

I honestly love it. Getting the size of heat pump right for the property is probably the most critical thing.

Oil-fired is now so expensive that it should be an easy sell to replace, not to mention the hassles of delivery.

Good point. A lot of the UK has piped gas, often built before natural gas was a thing (it would have been supplied with "town gas" which you can make with coal) and then retrofitted for methane last century, I remember as a kid seeing stuff marked as suitable for the "new" natural gas - the conversion had finished at about the time I was born.

But in rural areas it makes no sense. Running a single phase electricity conductor overhead for everything is affordable unless you live somewhere crazy like up a mountain or on your own island, but piped gas, sewage, etc. is just too expensive to justify. This is another reason to favour heat pumps, the heat pump runs off the same electricity as your household appliances, your PC, and your lighting, if you fit solar panels or add a private wind turbine (if you're a hilltop farm latter can make a lot of sense) that's all electricity and it Just Works™.

Super interesting - more info like this helps.

I have a 17th Century cottage and the folks came and just said that there was no point at all... maybe they were clueless!

I've heard this several but don't really understand the rationale. Can't you just put in a bigger heat pump? Or top up an air to water with an air to air?

I think that the issue is claimed to be that the pump will use lots of electricity trying to keep up with the heat escaping and therefore will not be economical.

But the same is true of gas, and in the UK at least they cost about the same per kWh of output heat (electricity is more expensive, but this is balanced out by the higher efficiency of the heat pump)

I think that this is a new(ish) thing though. When the UK was pulling gas out of the Irish Sea and the North Sea for domestic heating gas was much much cheaper than electricity. Then gas started being used at scale for electricity generation (the so called dash for gas). Then we moved to just in time import gas and things got very expensive.

So - things have changed.

Don't old UK full home renovations often take the house down to its studs? What would be limiting them from insulating well enough, or is just that full renovations are too expensive?

Most UK homes are built with brick or stone outer walls, and a big problem for heat insulation will be those walls. So that's a hell of a renovation, it's practically just tearing the house down and starting over, which is not a thing.

If you tore the bricks off my home, you'd see a thick layer of insulation, but this place was built in the 21st century and the actual structural loads are internal - floors are cantilevered off the lift shaft in the core while the bricks on the outside are mostly decorative. However if you tried to tear the bricks off my mother's 100+ year old house you'll tear the building down, the loads travel through that brick.

She spends more on utilities in a month than I spend in a year.

I've been watching some renovations in the UK, which I find really interesting, but I forgot that most homes are built out of brick and "tearing them down to the studs" really isn't possible. I guess the same is true with concrete (rather than brick) homes in Southern China (or why my mother-in law doesn't have heat in the winter and why it is so bloody cold to visit). They deal with that though by using things like Kotatsus, which I don't think westerners would find very appealing.

The only viable solution for those is effectively building an inner insulated shell in each room, which does work but loses interior space.

My grandmother lived most of her life in a poorly insulated brick terraced house with no central heating - every day she'd get up and light a coal fire in the grate. A lifestyle that belonged more to the 1890s than the 1990s.

Southern China has no central heating either. Old Chinese farm houses in the north still have coal, I stayed at an urban house in Tianjin in 1999 that still used coal honeycombs for heating. The kotatsu was invented in Japan to provide a space to heat individuals, so it’s kind of like that. You’ll still find it in use today.

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