Thats an interesting idea. The blower type fan i saw were extremely loud, i wonder if i could build an array of them (slower/quieter ones) and pipe the exhaust to a wooden frame that would hold the exhaust in the window.
Way too expensive setup for my usage but maybe for my next place. Hrm. Definitively noted.
Virosa this is a good idea. I was looking into larger industrial exhaust fans like this:
http://www.princessauto.com/en/detail/18-in-single-speed-ventilating-fan/A-p0772343e;jsessionid=YjEYeEHB2F0F3ZtnGxZTpI37.pal-prod-com1 for myself, but it would probably be too loud for your application.
Actual furnace fans aren't that loud, or they wouldn't be tolerated in homes. Why don't you try to find a trashed furnace and salvage the fan out of it to see how it does? It can't be worse than the plastic box fans, and can be ducted way easier.