Berlin is an absolutely miserable place in this weather if you commute or just trying to sleep at night. Like, you can't efficiently cool the apartment down if it's 20 degrees at night and there's no wind.
There was one day it didn't cooled down at nice for this year (when day temperature went close to 40 degrees). Other than that, for I sleep with all windows open and I create an airflow with two fans. The apartment gets cooled during night and during the day I just keep the curtains closed. It hasn't gone above 25 degrees inside the apartment during the day time.
AC is fairly problematic for narrow underground tunnels. This is one upside of the massive 9m diameter tunnels being used for a lot of new underground lines; way easier to ventilate. But, ah, not something you can really retrofit.
It could be worse, however: https://en.wikipedia.org/wiki/London_Underground_cooling
> Like, you can't efficiently cool the apartment down if it's 20 degrees at night and there's no wind.
I don't get it. 20 degrees at night sounds lovely. Get a window fan and you will be golden.Please don't sneer like this on HN. The guidelines make it clear we're trying for something better here. https://news.ycombinator.com/newsguidelines.html