Product review (5 stars): If you're having trouble with the fan being really loud and noisy...
If you're having trouble with the fan being really loud and noisy, double check your venting system to make sure it's open enough to support the air flow to the outside of your house. Also make sure that the two butterfly-looking white plastic flaps at the top mouth of the hood assembly have room to pop up inside your venting when you turn the fan on. I had to install this hood with a duct-taped conversion from the supplied tubing to our home's existing smaller vent tubing, and this hood sounded like a jet engine taking off. I winced to turn it on because it was SO loud. Today I started poking around  and realized the problems with air flow and flaps, and then saw here that you can just go without venting and let it act as a ventless system because of the charcoal filters. Fan is now able to pull MASSIVE amounts of air and it's SO quiet. Installation was simple and it is a great deal. We love our hood!!