Assuming commercial garage doors in fire stations, police stations, fleet garages.
Visual inspection and smoke pencil testing have shown that a significant amount conditioned air is migrating in or out through gaps between garage doors and their frames. This leads to drafts and discomfort in the door area, and also allows heating or cooling energy to escape.
Repair and replacement of weather-stripping of garage doors, is one of the most cost-effective energy conservation measures. Only commercial grade products should be used, and repair and replacement should be a regular maintenance item (generally every one or two years in high traffic doorways).