Product review (1 stars): Poor ventilation
This exhaust fan is poorly design, it is designed for recirculating or outside venting. I choose outside venting and did the modification to redirect the air flow to the top. I have the recommended 6" duct with one 90 and a short straight run to the outside.  The unit vent very poorly, the entire house smells while and after cooking. The fan is very loud on high and useless on low. Not recommended.