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Comment by OccamsRazr | Hacker News Reader

As someone who was in Europe for one of the heatwaves of recent years, and whose appartment was in one of these older buildings designed this ways with thick walls etc., I can attest that this only works up to a point. This design relies on there being cold air for the building to retain. However, in a heatwave it doesn't even get cold at night. The result is your apartment gradually heating over a period of days / weeks and turning into a sauna. It is not pleasant.

By the end of that summer I was dreaming about moving back to north america where air conditioning is much more common in rental units.

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What Europe needs is heat pumps and lots of them. More efficient heating, simply run them in reverse during a heat wave for refrigeration.

Most of the Continent is mild enough in winter that an air-loop heat pump will reliably heat throughout the winter, and these aren't more expensive to install than other heating systems, they're less energetically intense to operate, and they provide cooling on demand.

Problem with that is electricity is expensive in Europe. Of course as you know Europe varies a lot between Portugal and Romania. While the first has a balmy 10C in winter daily low, colder areas can easily have -10C, -15C at night. That's the minimum operating range of a heat pump. That's a 30C difference to work through. That's why they have cheap (Russian) gas, it has the biggest energy density (and nuclear). Ground-source heat pumps would work better in continental Europe but they are expensive to install (I have only seen them in new build villas).

Putting the gas into electric generators and using that electricity to heat is more economical than burning it in a furnace for heat, heat pumps are just that much better.

I agree that the national programme must be more detailed than just declaiming "heat pumps!" and calling it even.

I gestured vaguely at the existence of parts of Europe where cheap mini-splits might not be sufficient, let's just agree I'm talking about the places where they will be.

Apologies if my comment made it seem I disagree with you. Air-source heat pumps can definitely be used in many countries here, in fact they are already popular in the UK, and gaining popularity in Spain, due to their efficiency.

Yeah it's a temporary effect and once the walls have heated up, it actually makes it worse since it retains the heat at nighttime as well.

You need to drill down to access the constant temperature in the ground, to be able to really counterbalance the differences in the air temperature. Once you've drilled down I guess you can make a passive or minimal energy circulation system that would be much more energy efficient than air conditioning.

It’s called a geothermal heat pump and they’re quite efficient in the places they can work (which is basically anywhere that has enough temperature differential during the year).

I had an issue with this last fall - had my AC go out in the fall when it had been over 80F for the last few months. Outside, it would be 70 during the day and 50 overnight, but there was so much heat in my walls/floors that I literally couldn't keep my apartment below 80. If I opened every window and door, I'd get down to 75 or so, but it would be back to 80 within an hour, even when the temperature outside was significantly cooler.

It's great in the winter though. I haven't had to turn my heat on in years.

Northern Europe complains of the heat in the summer - they have nice radiators for the 7-9 months that need heating, Southern Europe complains of the winter cold because of the lack of insulation and central heating.

That’s so weird to me - why on earth would you skimp ion insulation? The stuff barely costs anything and it helps keep the place cool in the summer as well as warm in the winter

I grew in Southern Europe (around 30C every day in summer, more in full sun) when no-one had aircon at home and no-one had aircon in cars.

It's hot, you live with it. I'm sure it's worse on the other side of the Med.

It's one of the reasons the traditional 'siesta' exists and towns and villages are virtually dead until 5pm.

The issue I have with aircon is that it makes people ignore the local climate and, worse, actively fight it, which requires even more aircon.

Staying indoor in 24C air-conditioned spaces conditions the body so badly that even 28C starts to feel bad. I noticed this in my own behaviour and thought of changing it last month. For a change, I decided to drive without air conditioning. It felt bad for a few minutes, then it gets better and when I come back to a cooler place it feels like heaven.

Exposing yourself to the elements is greatly rewarding.

That's actually true. I had a car with A/C in southern europe which I traded in for one that doesn't have one (don't ask how). The first month was brutal but this year it's been already 30C+ and I don't even feel it.

People used to keep all windows open to get the cooling airflow. Now they keep all windows closed with aircon on.

30c in Castilles and Madrid is nothing. Siesta for that it's ridiculous. No one does that. What we do it's to have lunch. Siesta it's for days bordering 40 and up. Also, beware of the stereotypes. You will freeze up in 3/4 of Spain if you dare to get out in shorts and flipflops on Winter as many tourists do.

30c isn’t a point of reference for hot temperature.

> It's hot, you live with it.

For the average person, yes. But old and vulnerable people do die from it.

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