Obviously overkill/unneeded overhead, but most window AC units have a 'fan-only' setting that doesn't run the compressor. They aren't entirely sealed when not

Obviously overkill/unneeded overhead, but most window AC units have a 'fan-only' setting that doesn't run the compressor. They aren't entirely sealed when not in use, either, of course. It does seem like it be easy enough to build a box with a fan and some louvers, maybe even a frame to hold an insulated cover on the inside...