Originally Posted by rffx
The Whole House Fan we just installed is too noisy!
It is belt driven and we have changed the tension on the belt multiple times. It either does not turn or it is very noisy.
Any help or suggestions?
Any kind of blade creates noise when moving through air. There are all kinds of parameters that affect the level of that sound. Size, shape, speed, etc. Poor engineering design will yield a noisier fan than does good engineering design. Where in the price spectrum of house fans is the one you bought? If it was one of the more economically priced ones, sadly, you now have one clue why.