I bought this to replace an old fan that the builders had installed (my old one was only rated at 50cfm). I needed a new one because I was getting condensation on the bathroom walls since the old one was not moving enough air. I was able to install this in about 20 minutes from below and it works great. Perfect sound level to wash out any unwanted bathroom noises but not to loud so it's not annoying. It certianly moves a lot more air than the old fan. I liked this fan so much I bought another one and installed it in my other bathroom. Don't forget to insulate the cracks between the drywall and fan fixture to eliminate heat loss and help secure the fan (which helps reduce movement/noise). I used spray foam which worked great. I let it dry over night and then used a razor to scrape it flat and neat. Also, to make sure the bathroom fan acutally has air to move there must be a gap on the bottom of the bathroom door so the fan can pull air from outside the bathroom under the door and circulate the bathroom air outside. I cut the door so I have approx 1 inch gap from the bottom of the door to the tile floor (this also helps so the door doesn't drag or catch on any bathroom rugs). Once I cut the door and reinstalled it the fan actually got even quieter because it wasn't trying to work so hard to pull air. If you install a fan in a room with no means of "breathing" the fan can not pull air correctly and the motor will heat up and die very quickly.