One man's trash.......

I scored a fan just like OP's from a local university. OP scored big, those fans are great because they'll cool you when you're standing.

When I see tossed residential furnaces, I grab those squirrel cage fans. NOTHING moves more air for the size, and they're great if you're in a hot garage under a car, because the dirt that falls doesn't land on you, it blows away. Tilt em back a little and they'll blow a ton of air up your shorts, which has multiple benefits. Wire em up right, and you can even select speeds on some of em.