Labor Day has passed and Halloween is just around the corner. It’s undeniably fall, and winter is on its way. And the impending season and its usual inclement weather raise the same question in the hearts and minds of garage door owners everywhere north of the Florida panhandle: Is it a good idea to insulate my garage door?
You may think it’s a good idea. An insulated door will keep warm air in the garage in the cold winter months, so you don’t have to start your work day by strolling through an ice box. And when the sun inevitably shines again, your insulated garage door will keep the hot air out, leaving your garage nice and cool all summer long. At least, that’s what homeowners think when they are considering insulation. But it doesn’t work quite that way. If you’re thinking about insulating your garage door, you better do the math first. The math will tell you: Is it worth it?
For once the math in question isn’t about budget, either. It’s about the laws of thermodynamics and the rating of the garage door insulation that you need. Whatever the season, insulating your garage door is about slowing the transfer of heat. Heat wants to go from where it’s hot to where it’s cold, as quickly as possible. When it comes you your garage, that means heat generated inside the garage will want to linger, but in summer it means heat from outside will struggle to get in.
Garage door insulation is rated by the rate of heat transfer it allows. The higher a garage door’s R number, the better it is at slowing down heat transfer. A product with a rating of R-29 will retain heat much longer than a product with a rating of R-7. Unfortunately, even garage door insulation with a very high R rating doesn’t necessarily mean that your garage will stay a constant, comfortable temperature. The actual temperature of your garage in the winter depends on many things, including weatherstripping, possible leaks, and whether or not you supply the heat to the garage space that you hope to accumulate.