Yeah Joe, you're right .. a different scenario for every shape and size. And for sure yes.... those power fans are annoying and the motors burn out every few years, not to mention the electricity they require. That's why I prefer the Lomanco turbine vent. Moves up to 400cfm, has a lifetime forever warranty, and is SILENT. And yes sir, this is the most environmentally friendly choice. Hey, your last message was cutoff at the end. See ya late, alligator!