[LocalMan]

To cool summer bedrooms, blow the air out the kitchen window, and open the bedroom window. This will draw cool night air in the bedroom window. You may be sweating at 7 PM but you might need a blanket at 1 AM. This works brilliantly. And putting the fan out the kitchen window means the bedroom is quieter.

To heat winter rooms that have an underpowered radiator, blow the fan onto the radiator. The job of heating the room is the same as cooling the radiator. This works very well but the room downstream (on the steam line) will be getting less heat. In practice, that was the neighbor's apartment. The freezing neighbors complained to the landlord who eventually tracked it down to my place. Vigorous discussions ensued.

I also discovered that a HEPA filtration unit, even sitting on the floor, helped my allergies a lot. It was not cheap, but when I find my nose running again, it means that something had turned off the filter. For years I had thought that HEPA was a scam. Not so.