Has Anyone Built an Outside Air Ventilator?

[Tony Raine]

I like the idea of the filter screen replacement. If there is enough breeze in your area, this would be really energy efficient. The HEPA filter media is pretty restrictive.

thats where the box fan in the window comes in handy. you can just secure it in the window and not have to worry about blocking the rest of the window off. or set a "fan-on-a-stand" near the window to help pull in air.

i have a really neat 2 fan setup thats made to go in windows. it has 2 smaller fans (maybe 8 or so inches diameter each). you can have one on, or both on. it also has a slide-out on one side to fill in the rest of the window.

[Axaday]

I really like the Hepa screen idea. Thanks