I built this for myself. A few strips of Gorilla Tape and some ebay 4 pack for $45 MERV 15 20x20x2 filters taped together as a support for a 20" box fan from Lowes.
2600 sq ft home, filter is on the floor on the most open area of the house, which covers about 1/2 of the total space (39' Dome Home, 2 story plus a half story master, the area from the living room / dining room / kitchen to the master is all open area)
My air quality meter showed me in the low warning area for PM2.5 and PM10 before I started using this, half a day after starting it up I am in the good range across the board, plus the climate is more uniform throughout the house and I'm sleeping better from the gentle breeze and mild white noise.
I don't know if it would work as well in a boxier home, but a lot of people have said that it does for them as well, so it's probably worth it if you have $65 to burn and the space for the filter cube setup thing.
