Product review (5 stars): Keeps cold air out !
I live in an old house and have a large laundryroom/"artist studio" that just wouldn't stay warm. I'd heat it, but half an hour later, it would be cold again. I had the walls, ceiling ,and floor insulated ,which helped ..but didn't solve the problem. My next expensive attempt at maintaining the heat was going to be installing double pane windows. At the time, my budget didn't allow for the new windows, so I opted for changing the dryer vent. What a difference it makes ! The room now stays toasty warm !