Air conditioning on trains

Does anyone else share my abhorrence for trains which have sealed windows and air conditioning?
There are two main problems in my experience.
One is that if the heating/air conditioning goes wrong there is nothing whatever anyone can do about it. One of the trains on the Norwich line had a faulty heating system in the winter which was blowing out extra cold air on some of the really cold days, so that you were chilled to the bone even sitting in an insulated ski-jacket.
Now we have the problem of "summer". The train companies seem to think that we want the train kept at exactly the same temperature whether it is winter or summer, and so (quite unnecessarily) they cool the train down on a nice warm day, so it's like getting into a fridge. What they don't seem to realise is that in the winter you get on in your thick socks and shoes, woolly sweater and long-sleeved shirt. Then you want the temperature set to the sort of level at which it's comfortable to read, without having to peel off all your warm clothes.
In the summer, by contrast, you arrive lightly clad, with sandals and short sleeves. On a warm day you probably don't even have a jumper or jacket with you. Three minutes into the journey on this refrigerated train you are perishing cold. You ask the "conductor" (meaning the guard) whether he can make it a bit warmer, but the answer of course is "no". There are no controls. The thing is just set at a certain temperature, presumably the same temperature winter and summer.
What a waste of energy! Most of the time we wouldn't need to be air conditioned: the outside air would be perfectly fine. And even if we do have air conditioning, it doesn't need to be working like a fridge to make us into blocks of ice. It could be set five degrees warmer, and we'd all be just fine. 21º in the winter and 25º in the summer would seem a sensible system to work on, to minimise energy and maximise comfort.
But best of all, let the human beings have control instead of the machines. Because, after all, we're the ones who have feelings...