Beware! Although the literature states that the hood works with a 7’ 7 in. ceiling height, it does NOT. If you are using this hood for recycling air, not ducting outside, you need a 7’ 10 in. ceiling height or the vents will be covered.  You learn this in the owner’s manual AFTER you purchase it. You need a 24 in. outer duct and GE claims to not make one. Very disappointed to research this and be led astray.