And they connect using relatively thin tubing? (drill through wall, poke tubing/piping through, seal with summat) rather than have large bore piping through wall, right?

I am just pondering one for my room, as it is the ONLY room in the house that gets the sun from dusk till dawn (3 walls basically constantly getting sunsoaked, and even at 1am it is still over 30deg in here - don't help I have the hotwater pipes under me floor boards and the boiler on the otherside of the 4th wall either )

Don't really want one of them portable ones cos it means you have to have the window open several inches to have the tube hanging out - trouble with that is again cos of my window location, if it rains, is 99.9% of the time comes in my window if it is open