AI6YR BenTrying to deal with wildfire smoke? Here's the best thing since sliced bread for massively improving the air quality in your room/apartment/house/etc.
How to build your own Corsi-Rosenthal Box
Stephen Dioxide 
@ai6yr This is my cue to observe that you can scale this up by taping the filter over a window or two, and then placing a fan facing out in the farthest window in the house. I've done this two summers in a row.
NilaJonesHave you done that when it was super smoky out? Did you get smoke free air inside?
If this method workw for you, your house must be built extremely tight! Most houses are deliberately built to leak a bit of air, so people don't suffocate in their sleep. (It's a building code thing)
So the fan blowing out brings in air from all those little deliberate gaps, around the doors and windows, primarily
And the air doesn't come in through the open windows with filters, because the filter provides more resistance
But if your house is tight enough to work, that's great! And you're probably getting some very needed fresh air
Another option, for more normal house, is to put the CR box or other air purifier in the window, and seal around the edges. That way the fan and the filter are in the same window, and you are blowing clean air into the house
I've been doing this since 2020 in my apartment, and it works great
@NilaJones @ai6yr My house is old, so I'm sure it's not totally airtight. Still, any improvement is progress. When the smoke was bad, I noticed symptoms when I was outside, and not when I was inside, so it has to have been working to some extent.