The filters used to create the box should be rated MERV 13, which is efficient enough to filter out very small particles in the air, Creed said. "I have personally purchased them at Ace Hardware ...

Q: I would like to put a filter of some sort over the fan area of the computer (on the outside) to help keep out the dust/dander. Would this be a bad idea?

For $150 or less, you can build a Corsi-Rosenthal Box air filter to lessen the impact of wildfire smoke indoors. Here's how. Or even cheaper if you have these common home supplies.