Lasko Cool Colors 20" 3-Speed Weather Resistant, Energy Efficient Box Fan, B20309, Purple

I use this fan to draw out under house odors. It is mounted on the crawl space entrance door, turned on low and forgotten. It runs continuous and last about three years. The motor holds up far beyond 3 years but the plastic blades are warped from the sun, so even still running the blades don't push air any longer. Still a great purchase, other fans I've tried didn't last a year, The motors would go out on them.

I used this to build a Corsi Rosenthal box. It's an amazing kind of air filter built inexpensively that's as good as an extremely expensive air filter. This fan is often recommended because it is just right, and it is! Excellent. A relatively inexpensive fan that can be turned into something worth forty times more. At low speed, the optimal one, I have to look over to know it's on.