Product review (5 stars): Very energy efficient!
I have my washer and dryer in a small bathroom. In the winter, the room was always like an ice box because the old style flapper never sealed well. I installed this last fall and WOW, what a difference. The bathroom is always the same temperature as the rest of the house now and I am am not wasting all that money on heat. It was a little awkward to mount to the beveled siding and it is only plastic (like most of them), but works flawlessly! No lint build up after 5 months.