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0 pointsglobular-toast8mo ago0 comments

The trouble is if you just retrofit aircon with no other changes you actually increase the outside temperature, possibly by more than 2 degrees[0].

This has worried me since I was a child. If everyone has AC it's a race to the bottom as it gets warmer and warmer, AC has to work harder, using more and more energy etc. You end up with hellhole cities where you can't be outside at all. It's simply not sustainable. We have to do other things like having green spaces, less tarmac, shutters on windows etc.

[0] https://www.euronews.com/green/2023/08/30/fact-check-is-air-...

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rightbyte8mo ago

Oh that is interesting. A greek guy I know said to me that cities 'radiated heat' some years ago and I kinda didn't believe him.

Localised to alleyways etc the effect can probably be even worse.

mike_hearn8mo ago

The urban heat island effect isn't to do with AC specifically. It's a mix of tarmac absorbing heat during the day then re-radiating it at night, a higher population density and a higher density of machinery.

The night time re-radiation has the effect of bringing the min closer to the max readings, and so making it look as if temperatures are going up, even when max temps aren't changing much. The same effect can't be seen in rural places where there's less tarmac.

globular-toastOP8mo ago

AC is an example of "more machinery", so it does contribute. But I would also argue that the redistribution of heat is itself harmful and AC is a horrible tragedy of the commons solution to the urban heat island problem.

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