OK, BUT, we’re talking UK. here, probably just a few warm weeks in summer. Is it all really worth it?
I hear that all the time. We've had hot weather on and off for more than a few weeks so far this year (how quick people forget) and it will remain hot in August and even September going on previous years.
I bought a car with aircon as a 'must' back in 1997, and everyone thought I was mad. Then it was 'only hot a
couple of days a year'. Now, of course, nearly every car has aircon - and why wouldn't you? I've just driven throughout Europe for two weeks in 30-34 degree heat, and I am not going to drive on an autobahn with the windows open!!
It doesn't have to be 30 degrees at street level for it to be totally uncomfortable on the tube. I do however agree that the doors being open can cause an issue, but it works elsewhere so I am sure a decent HVAC system can cope - and the doors will stay shut on those trains if people don't alight or board (and autoclose after as little as 10 seconds for the very reason mentioned).
I've often wondered why we can't air condition stations on the underground. If you can't do the trains, doing the stations themselves would make waiting for trains a lot more pleasant - and also allow more cool air into the trains when they stop. For all but the sub-surface lines, this might actually solve some of the summer heat problems.
You wouldn't need to condition the whole station, but just certain areas. I am sure anyone with a scientific knowledge could work out the movement of air to ensure that you can cool certain zones effectively - even if other zones remain warmer.
Even just reducing the humidity would make people feel a lot more comfortable.
And buses - why the hell can't they be air conditioned? They're AWFUL in the heat - and especially when the sun is right on the top deck. If you're stuck in traffic, as buses often are, they're almost unbearable and you're better off walking.