I have one in the garage - it was my grans as she was old and elt really unwell in the heat. It worked ok ish, it is a stand alone unit and you stick the tube out the window (like with a tumble dryer) so you end up with the window open
I always like to create drafts by proping doors open and using fans
We've got two. Bought the first one the year DD was born, as it was regularly 30 degrees in her room, and the second one a couple of years back when it looked like we'd get some hot weather and need one for our bedroom as well (it didn't get much use). We tend to put them on for a while around respective bedtimes to get the room down to a sensible temperature. Having the window open isn't a huge problem as by then we've got the curtains closed and keep the cold air in and the warm out in that way.
They are big ... but on wheels so easily moved between rooms on the same floor. They live in the loft in the winter, I bitterly resent having to get them down each year, and the space they take up - then it gets hot and I love them!
No idea of brand on either of them, but you need to make sure they're the right rating to cope with the size of room. Our first one is the more powerful one, as although the room was small it's south-facing and has a massive window.