Well yes, I meant preventing that hot air from circling back inside through the window, since these usually come with a kit to fit into the window, but aren't particularly airtight.

Also I'm genuinely amazed at how fast that thing fills a bucket with water from the condensation, it's ridiculous. I live near the sea so 70%+ is normal, but seeing it was still surprising.

I have mine in the living room and it pulls in air from the rest of the house, air filters in from many different places.