Jonathan: Hmmm good point about the replacement air. The room is downstairs in my "basement" its a finished room circa 50s/60s probably built without permits (just a guess unless plumbing codes changed dramatically, i.e. requiring air vents for each drain), and was thinking and yanking incoming air from there. Had a friend do it with just a thermostat and says it works fine, I'm a tad more worried about humidity issues than temperature ones, but who knows, maybe it'll balance out in the long run that the temperature being vented will keep the humidity in check (however I would think the night time humidity issues might then become problematic).
Hell I might be able to pull air from upstairs too, but I really would like a flapper that closes off when air isn't being pushed out. Although I would think a vertical air pull might end up having all my heat go that direction
