After 3 yrs of going deaf with this re-circulating exhaust fan my visiting brother who could not stand the noise checked it out and discovered that the front cover plate which should only be left on for a fan exhausting to the outside atmosphere had not been removed (obviously oversight by installer, but how many others don't work due to this reason?). I had wondered why the filters had never got dirty - reason being the product has never worked for the purpose it should have. That made it work at last however did not address the noise problem. Still sends us deaf. I bought it because I'd had one before and it was good but I'm put off for future purchases.
Reliable, inexpensive
Horrible noise, you can't watch tv or have a conversation