I live in an area with not so great air quality and no AC. We have little air filters inside the rooms, but at night we have to let the cool (and dirty) air inside to cool down the house.
I’d like a solution to blow air in while also filtering it - but aside from one Amazon listing and makeshift solutions with zip ties, I haven’t seen great options.
Any recommendations you have?
If you’re relying on the breezes to let air in, then a furnace filter that is the same size or a little bigger than the opening of the window should work. You’ll get a little less air, but a HEPA filter will let only clean air in if it’s wedged into the window opening or taped to the outside.
If you’re doing a box fan with furnace filters, do at least 3 filters and some cardboard to make a cube, put the cube outside and the fan in the window opening, and block any gaps around the fan.