I have been running 3 fans, two at opposite ends of my run and one in the gable of my coop. This morning I pulled them all out and cleaned them and believe me they were pretty dusty. Most of the fans sold these days can come apart for cleaning so I just put the covers in the tub and washed them down with a brush and shower wand. I wiped the blands and got all visible dust off and re-assembled them. They look good. Take the time to clean them and you will have the peace of mind you are not running a fire hazard in your run or coop. Taking the time to keep your flock safe - priceless!