> The UK typically doesn't need air conditioning

I don't know where you live but UK summers were unbearable even when I was a kid. Buildings are engineered to trap heat, so the heat doesn't dissipate at night and every day the indoor temperature rises, and rises...

At least they removed the need for planning permission recently. The problem is that the places that need AC the most (flats) will probably not be able to get it until the leasehold system has been abolished.

> > decarbonizing heating

> What does this mean?

Presumably it means heating using electric heat pumps rather than gas boilers. This also solves the AC problem. I don't think this is viable for most people. Heating was never the problem anyway, at least in the south winters are mild.

> I don't know where you live but UK summers were unbearable

well, i live in lincolnshire and used to live in london. i usually have a fan on for a few weeks over summer, but that's it. where in the UK did you live that the summers were so unbearable?

> Buildings are engineered to trap heat, so the heat doesn't dissipate at night and every day the indoor temperature rises, and rises

This makes insulation sound like a bad thing. The more insulation you have the less the indoor temperature is affected by the outside temperature.

> The more insulation you have the less the indoor temperature is affected by the outside temperature.

Insulation isn't magic, over many days of hot weather eventually the building will reach equilibrium with the average outside temperature. This means it will be cooler indoors than outdoors during the day, and hotter indoors than outdoors at night.

However, the nights are specifically when you want a residential building to be cooler, assuming the inhabitants are not at home during the day. So the insulation actually makes the building hotter from the perspective of the inhabitants.

A common scenario is to have unshaded solid walls exposed to afternoon sun. Without insulation the inside of the house can be high all through the night. A good effect of insulation in summer is to prevent that effect. Important to note that it would be standard to allow cooling airflow in the morning.

Unbearable is a stretch. I live in Texas and don't use the AC every day in the summer. The human body can adapt if you dont constantly climate control

I think you're right, and in addition to that there is also a lot we could do other than AC. Just having some shade from trees already helps a lot. Modern cities can be a man-made hellscape with regards to heat. But we did that to ourselves.

I for once feel better overall when it's 35c outsides airco or not, but people tend to think I'm being funny about that

It's fine if temperatures get lower during the night, but 25°C at night and 35°C during the day leaves little for cooling the infrastructure (roads, buildings), and constant warm temperatures are unbearable if you cannot even get in the shade when you want to cool off. Then, 35°C is also very hard to manage with high humidity.

That's only a few weeks a year. The UK isn't Florida yet. And besides modern AC is incredibly efficient. The stuff that's cleared to sell in Europe has incredibly high standards.

> UK summers were unbearable even when I was a kid.

Not to be that guy, in the last 20 years, 27 was considered a heatwave.

> Buildings are engineered to trap heat,

I mean Victorian buildings were engineered to let in light, and have good ventilation. Hence why each room has a huge sash window, an airbrick and a fireplace.

> The UK typically doesn't need air conditioning, so why would people spend money on it? Yes, I know this recent summer was exceptionally hot but people don't react that quickly to changes.

We are? It’s becoming more common and we had a few bad summers and earlier this year too. The heat wave a few years back killed my dad.

Given there’s a push to swap heating systems for more efficient ones, air con units are being looked at a lot more.

> The UK typically doesn't need air conditioning

Nobody "needs" air conditioning, but even a modest window unit provides a huge improvement in quality of life whenever it's 80+ outside.

> Nobody "needs" air conditioning

It can be considered a medical necessity for people with certain conditions like anhidrosis, asthma, COPD, kidneys disease, or cardiovascular issues. It's also a huge medical benefit for people with terrible allergies who wouldn't be able to open a window even when that'd normally help cool the house.

80 plus in UK would be a bit of a stinky situation

> The UK typically doesn't need air conditioning, so why would people spend money on it?

We had 6 heat waves this summer. Parents were booking hotels just to keep their kids cool

We also had heatwaves in 2022, 2021, 2019, 2018. 2024 wasn't bad but was still the 4th hottest year on record.

You can absolutely bet the better-off middle classes are installing aircon. I know many. If more people could afford it they would get it

It's the humidity too not just the heat. And how after 3 or 4 days of high temps, our houses just do not cool down at night because they act like radiators. Humid 25c+ nights suck for us

> decarbonizing heating

I believe this refers to switching to high-efficiency electric heaters like reverse-cycle AC units (also known as "heat pumps"), rather than oil heaters or ducted gas heating.

The majority of UK homes are heated by gas-powered boilers that pump hot water through radiators in each room. Often hot water is heated by the same system.

Decarbonisation usually means replacing that boiler with a heat pump which uses electricity to heat water.

Thanks. I didn't know about the UK specifically but replacing gas boilers with heat pumps makes a lot of sense.

Very few places "need" air conditioning but it doesn't take very days where it's 80+ outside and hotter inside to convince me that the per-day cost of AC is worth it. And that level of heat is nothing new.