Any opening you can see or feel in a door, window can have a big effect on your energy bill. For example, a pair of exterior doors with no weather stripping can have an opening of ¼” where the doors meet.
While this doesn’t look or sound like much, on a 6’ 8” high pair of doors, it adds up to the equivalent of a 20-square inch opening. A similar gap in just two average-size double-hung windows, where the sashes meet, would add up to the same 20 square inch hole! In a typical setting, this 20 square inch hole would allow over 40 cubic feet a minute into or out of the building. This air infiltration could cost as much as $54 per year in heating and cooling costs. If you see any bad seals in doors or windows, let your facility manager know, they should be repaired at once.
Ed Saleem, SEA Engineer