I wish we in the UK could mobilise half the outrage we express about "air conditioning is a waste of energy and bad for the planet" and target it at AI datacentres, short haul flights, the beef industry, fast fashion or golf courses. They all do huge amounts of planetary harm without the justification of potentially saving lives in a heatwave.
Also no one seems to complain about air conditioning in cars, but as soon as anyone starts talking seriously about putting it in buildings like hospitals, schools or workplaces suddenly everyone's an armchair climate activist
@afewbugs Yesyesyes. Heating is also air conditioning. I also wish the UK had not backed (with subsidies) heating-only heat pumps, but instead encouraged use of those which swing both ways, which my Canadian relatives have. Astonishingly short-sighted.
Jun 30, 2026, 9:01 AMFor private residences:
Putting in a heat-only pump is a very minor modification. You can use all your existing radiators.
Putting in cooling requires replacing all of them and the internal pipes because of condensation. Its major building work.
By the time your house is insulated well enough for the heat pump, you can vet through a heat wave by opening windows at night and closing them in the day.
Institutional buildings however, need to make the modifications.
Jun 30, 2026, 9:16 AM@Gaolaitch @celesteh @afewbugs
The subsidies appear to have fixed that recently.
I'm not 100% convinced that it needs a complete overhaul. You don't want to run radiators at levels that will cause condensation (at least, not regularly) but running some cold-water pipes to a couple of fan units in key rooms seems feasible. I'm looking at doing that for our house: we have three floors and the boiler is in the middle, providing cooling for the room containing the cupboard with the boiler in it and the rooms above and below would make a huge difference in heatwaves.
Jun 30, 2026, 12:55 PM@Pionir @david_chisnall @Gaolaitch @afewbugs
The UK in specific has a few major structural issues.
Most homes are very poorly insulated, especially the homes used by lower income people, which tends to make them ill-suited to heat pumps for heating.
There were subsidies for this, but not a certification scheme, so a lot of people had extremely shoddy work done and are now having major, expensive problems with their homes. (This has been covered in several recent editions of Private Eye.)
Heat pump subsidies also have had a lack of oversight. I made a down payment that was equal to the subsidy to heat pump firm which immediately went bankrupt.
I put in a heat pump anyway, because it uses so much less energy. I failed to account for how extremely subsidised gas is. My overall energy consumption is much much lower, but electricity is so much more expensive that my bills have gone up.
This is essentially a luxury good. For home energy policy in the UK to work, we need to commit to minimum standards for habitable homes. The Tory government was absolutely against that and I don't think the situation has improved under Labour.
@celesteh
In my opinion if the energy price difference was sorted out even a really badly insulated home could be effectively heated with a heat pump and would still be better environmentally than gas in the same home. It's really stupid that right now you have to pay more for doing the more efficient and beneficial thing ☹️
Jun 30, 2026, 1:05 PMThis is still way more major building works than what I had done. If it turns out that the lack of AC is a problem in future, I'll take another look. Right now, I have heat in every room. Having cooling just in one room would probably be good, but not required at the moment and also would no longer be a central system, at least for cooling.
@celesteh
Fair!
Jun 30, 2026, 1:08 PMThings may have improved since I got mine, but the ones available when I got mine were quite slow and thus are ill-suited to uninsulated houses.
ASHP doesn't make an logical or practical sense for me. 4 bed detached home built around 25yrs ago. I've upgraded the insulation massively. Going from 100mm to 300mm in the loft, when I've opened up and moved walls upstairs to do other work, I've installed 75mm acoustic insulation in all of the walls. This makes the upstairs fantasticly warm in the winter. I need a better way to move air through the house upstairs to shift the heat in the summer though.
To install a heatpump, I need to remove the newish boiler that was installed a year before we bought the house. That also means adding a water heater and because we've got solar and batteries... a solar water heater. We also need to rip out all of the pipework to the radiators because it's too small and fit larger radiators because of the lower flow rate... the radiators that we replaced with better and more efficient ones when we bought the house.
We also don't qualify for any grants because the house is 3 points into a band C on the EPC and grants only apply to D or lower.
We'd also have to pay to have the gas completely removed because we would have no need of it at all... that's a couple grand in itself just to save the 30p daily standing charge.
Worked out... it was going to cost us well North of £22000.
Just not worth it when you factor in we spend at most £650-700 a year on gas and the heating is turned of from the end of April to early October.
My neighbour did it though, back on the old eco 3 scheme because they upgraded his cavity wall and loft insulation and installed the ASHP for virtually nothing... he's also got solar and batteries, plus 2 EV's and he's using between 40-50kwh a day compared to our 13-14kwh, his solar array is the same size as mine at around 4kw which on the best days will only produce around 28-29kwh.
So he's still got higher bills than we have.
@celesteh @Pionir @david_chisnall @Gaolaitch @afewbugs
The Tories at one point actually tried to address home energy efficiency - they had a plan that from some year or other, any home sold or rented would have to meet EPC C or above.
Then it was dropped. Not sure of my timing, but I think it was Sunak's big speech about cancelling net zero stuff. Most of what he "cancelled" never existed in the first place, but that one did.
Jun 30, 2026, 9:53 AMBrit turned Kiwi here. A reversible air-air heatpump into your most used room is simple, cheap and very effective. They're ubiquitous here. Quick, easy, efficient harm reduction, both fossil fuel and comfort/health.
@Niall @Gaolaitch @celesteh @afewbugs UKanian here. When we converted unused rooms in our garage block to a studio for my partner to work in it was too far from the house to extend the central heating system.
Rather than resistance heating the obvious solution was a small standalone air-air AC/heat pump which in practice we have only needed for heating (so far).
It's perfectly adequate to provide HVAC to a single room, which could be a life saver given where we are taking the planet.
@marjolica @Niall @Gaolaitch @celesteh if you don't mind me asking, how much did single room air to air cost?
@afewbugs I'm curious, too! @marjolica @Niall @Gaolaitch @celesteh
Jun 30, 2026, 11:59 AM@NatureMC @afewbugs @marjolica @Gaolaitch @celesteh it has been years since we bought one. Maybe US$1k for a 3kW* one and half a day of a professional's time to install?
*that's output power. Input electrical power is much less.
@Niall thanks!
@afewbugs @marjolica @Gaolaitch @celesteh
@NatureMC @Niall @afewbugs @marjolica @Gaolaitch @celesteh
Prices in the UK start at about £1300 installed, but I expect most installers are now booked up until autumn comes around.
@celesteh @Gaolaitch @afewbugs USian butting in-we retrofitted our 80 yr old house with heat pumps three years ago. Where I live AC is not common. It was very hard to find a heat pump to just provide heat using existing hot water radiator system. For main level, heat pump unit is external to house, feeds in to attic unit, with insulated tubes to small vents in ceiling. Does heat or cooling. Works well! One other room has wall unit mini split.
We upgraded insulation to R30 20 years ago, to buffer temp changes and didn’t need AC. Put it in to take advantage of incentives when we could and thinking of the future. Our house (unlike most here) is passive solar, built into a hillside with large eves so little direct sun in windows in summer but good winter light. Best compromise in this climate for both warmth and cool, but still, even with good insulation, it cannot keep up in heatwaves. There are only so many clothes you can take off.
@IcooIey @celesteh @Gaolaitch @afewbugs I was also told that the heat pump couldn’t work with existing radiators unless an extra heater was added which would be very inefficient - so took the plunge and replaced them all with floor heating
@mkoek @celesteh @Gaolaitch @afewbugs Every situation is different. It helps to share what worked for each of us to show the different factors to consider, tech available in different places. We now have a ridiculous system where fuel oil boiler (heat, hot water) remains, used sparingly; Heat pump hot water (used primarily); heat pump heating/ cooling (used intermittently; wood stove insert (used sparingly); whole house fan; full tree cover.
@celesteh
You can also just install air to air units and bin off the radiators leaving the pipes under the floor. You need new pipes for the Aircon refrigerant but much less disruptive if e.g they just have to run to the nearest wall to get outside. It's what I did. You do need a way of heating water though.
@Gaolaitch @afewbugs
@celesteh @Gaolaitch @afewbugs Except not. We always managed with the opening the windows at night and closed during the day thing but if the nighttime temperature barely drops below 25 and the daytime gets up past 35 for a week, as it just has, the house will warm through eventually even with external shutters keeping the sun off the windows. The living room got to 27 and the bedroom to 29. My ability to function and sleep is decidedly compromised then.
@celesteh @Gaolaitch @afewbugs "Get through a heatwave by opening windows at night".
Are you my 73 year old mom? No. There is no cooling off the house, nevermind a highrise apartment, when the temperature remains at 25C or more overnight for days or weeks.
Signed, a Canadian who has lived through cold winters and hot summers with 35C+ heatwaves for over 40 years. You NEED to get on A/C now.
Jun 30, 2026, 10:14 AM
@Gaolaitch @afewbugs Brit in Italy here. Our air cond also does heating. It’s quite normal here for more recent units. Only thing is the air conditioning is only fitted in three rooms not in kitchen and bathroom. The apartment building also has centralised heating.
@afewbugs What pisses me off about the AC in offices is not so much that exists, but more that it's crap.
A common experience is that the office burns carbon in order to be uncomfortably cold, which actually it's a nice warm day outside! Having to carry cold weather clothes to wear in the office on a warm summer's day is madness.
@TimWardCam I do find it weird how many universities (not just my current employer, the one I was at before too) are constantly launching cost cutting redundancy drives but still manage their heating so badly. There's always a period of a couple of weeks in spring when the temperatures have risen outside but they haven't switched off the heating yet, I don't know how much gas they must be burning through to roast us all. They'd probably do just as badly with air con. But we don't have AC in the offices, just the labs, and the windows don't open so it's been getting up to 35 in there and personally I'd rather take too chilly than that
@afewbugs @TimWardCam At one university I worked at, there was one room that had a large AC in one corner that couldn't be switched off, even in winter. In winter it competed with the normal radiators, plus the portable radiators we had to try and keep warm, and we all went in wearing several layers of clothing, but were still freezing. Reading the university's emails bleating about energy use was pretty annoying under those circumstances.
@HollieK72 @afewbugs @TimWardCam On a somewhat smaller scale, after years of trying it seems still to be impossible to actually turn off the main meeting room HUGE screen in the #sustainability dept at my uni...
@afewbugs so often cars get a free pass.
@afewbugs you don't have cooling shelters out there?? No wonder people are suffering.
@pencilears no the problem is our infrastructure isn't designed for this heat - there's no air con and our buildings are actually designed to retain it. So you have the crazy situation where people are being taken to hospital with heat exhaustion and it's 40 degrees in there
@afewbugs That's awful!
Around here places like hospitals, libraries, and other public buildings, all have aircon and people are encouraged to seek out those spaces if they're homeless or otherwise need a cool place to be during the day (they'll call it a "cooling shelter" but that's mostly to encourage people to come in)
@pencilears sadly we're just not prepared for these temperatures and are coming up on two decades of deliberately not investing in public infrastructure for ideological reasons
@afewbugs austerity is a mind-poison, I'm sorry you're having to deal with this.
@pencilears We have this in France too (still not enough). But only after 20,000 direct heat deaths in 2003, when the corpses in some places had to be piled in hotel fridge rooms ..
@afewbugs I really wish we could also connect the dots in aircon being most needed in the summer when its hot and sunny and you could probably power a lot (if not all of it) with solar! We used 15kW power per day last week running the aircon in our boat, every watt provided by the sun, zero emissions.
I blame the car makers.
AC now comes "standard" in all cars: you get to pay for it whether you want it or not. And then you can justify using it by saying, "the car came with it".
Jun 30, 2026, 2:48 PM@afewbugs Everybody knows the AC in a car consumes no energy, as the engine is running anyway ;-)
It is needed when there is peak solar. The objection is stupid posturing. They are in any event very efficient heaters.
@afewbugs Also, by now A/C should even have a negligible or positive climate impact:
Jun 30, 2026, 9:24 AM@afewbugs the problem here is more that people have to accept the facts first.
Heatwaves are the new normal so are cold snaps.
That leads to accepting that climate change is, in fact, real and that a lot of damage is already done that can't be undone. A lot of "businesses" have no interrest in that. On the other hand those "businesses" who belong mostly to the same people have a huge interrest in destroying personal computing and implanting the believe in the "god machine" into the wider public.
@afewbugs if you have a solar system the AC is basically free and carbon neutral.
@afewbugs but it's new (to us) and therefore eeeevil!
@andygates I think you've hit the nail on the head there, honestly
@afewbugs Yeah... 29 Euro flights across Europe should not exist.
Jun 30, 2026, 8:38 PM
@afewbugs
And we can mitigate the harm by investing in solar panels which would also help with affordability, which is also an issue with how high energy prices still are.
@afewbugs
> "air conditioning is a waste of energy and bad for the planet"
Yeah, the decline in the standard of teaching basic physics is so gross...
AC units once produced do not "waste energy". They can move solar energy that already is here using solar energy that is coming here.
@afewbugs 🎯 This, so much this! In every country!
@afewbugs plus air con can be turned into a heating system with minimal expense and it's much more environmentally friendly than a gas furnace anyway
Jun 30, 2026, 12:37 PM@afewbugs Is there actual outrage against air conditioning or is it rather "anti-woke" outrage about purported air conditioning outrage? Because I haven't seen any of the first, while I've seen quite a bit of the latter. Might just be the circles I move in.