Product review (4 stars): Vent A Hood cold air blowing in!
I installed my Vent A Hood three speed 36" insert into a wood hood, last summer (2014). This winter I froze my backside because of cold air blowing back into the kitchen. The original installation had a metal Vent A Hood wall cap. Cold air blew right in.  I changed that for a plastic, deeper (less cold conductive) cap and air was still blowing in.  I can hear the inside damper opening when the unit is turned on, but I can't determine why I am still getting a draft.  Any help and suggestions would be appreciated.

Thanks