@jon That's a good plan. If your aircon is the portable type, as mine is, colleague suggested insulating the venting pipe to the window. It does radiate a lot of heat back into the room. Will try that myself at the weekend but have probably missed the most benefit.

@wamonite I discovered earlier while using the aircon as a big fan pointing out the window (with cooling turned off, I’m not a monster) that it also dumps warm air from inside out through the exhaust hose in that mode. This is ideal because my exhaust hose is hooked up to the extractor fan vent in my kitchen.