I live in Texas so air is a must, but now that we've moved, they are suddenly afraid when the air kicks on. I think they'll get use to it. It's kind of funny, they'll be trotting along and then the air kicks in and their ears move for take off and their eyes get big and then zoom out of the room.....I see a daily improvement though. Sad part is its loudest in the bathroom where I've put their litter box. I'm wondering if they are going to be afraid to use it in there. Going to give it a week, but may have to move it - I don't want the guys to be afraid to use the toliet, poor boys.......