I have central air but I hate high power bills so I keep it set on 78 degrees. That works just fine downstairs with the ceiling fan but my sewing room is upstairs with no ceiling fan...ITS HOT! So I bought a small window unit, run it on low (only when I'm actually sewing in the room), and put a small fan in front of it, close the door, and away I sew! When I'm done sewing, I turn off the window unit and open the door. the fan blows the cooler air into the rest of the upstairs.