I put a small standup AC unit in my trillium
, with it venting out the window over the stove. I decide before each trip if its worth lugging along - but didn't have to cut holes or make any modifications to put it in.
For the vent i took a piece of corrugated plastic (picture an election sign) and cut it to the shape of the window, i then screwed through it to mount the AC vent hose, and cut the hole in the middle for it to breathe through. The plastic is held to the frame with metal Duct tape so it seals completely.