Today’s garage-door manufacturers add enough insulation to their most expensive doors to make them as energy-efficient as your home’s walls. That might sound like a good thing, but for most homeowners, it isn’t. In short, you won’t realize any additional energy-saving benefits by adding the most insulated garage door, independent experts tell Consumers Digest.
But that hasn’t stopped manufacturers from introducing high-performance garage doors that rate as high as R-20.4. (R-value indicates how well that a product prevents the transfer of heat and is based on tests by each manufacturer.) The 21 garage-door models that have R-values that are equal to or greater than what’s mandated for the walls in most homes (R-13) are nearly twice as many as existed 4 years ago.
Yet home-energy experts tell us that upgrading to an insulated garage door will do nothing to lower your home-energy costs and will do little to improve the comfort level that’s in your garage.
Unfortunately, the price of all garage doors, regardless of whether they include insulation, has gone up by at least 6 percent and by an average of 15 percent compared with 4 years ago. The increase is because of a rise in materials costs—particularly steel.
INSULATION OVERKILL. The steep increase in R-values among steel garage doors primarily is because more manufacturers are adding high-performance polyurethane insulation to their doors, which often doubles the R-value. For instance, Clopay, which had a maximum R-9 rating on any of its doors 4 years ago, now has an industry-high R-20.4 rating on one of its models because of the addition of polyurethane insulation.
But all seven independent home-energy experts whom we interviewed insist that the extra $213–$536 that you’ll pay to get a steel garage door that has polyurethane insulation isn’t worth the added expense in most situations.
“An attached garage is a space that’s outside of the home’s thermal boundary, so an insulated garage door isn’t going to make an impact on your home’s heating and cooling costs or its comfort,” says Anthony Stonis, who is the owner of Building Energy Experts, which is a home-energy audit company.
More Doors Have Touch of Glass
Building codes require that the walls and ceiling that separate your home from an attached garage must be air-sealed and insulated. For this reason, independent energy experts say, little, if any, heat transfers from the house to the garage, so in the winter, your garage has little or no warm air for an insulated garage door to retain. The reverse is true in the summer when an insulated garage door can slow the transfer of heat into your garage from outside, but it can’t cool the air that’s inside of it. Consequently, independent experts tell us that an insulated garage door will make your garage only a few degrees warmer or cooler than the outside air at any time of year. And because your house is insulated from your attached garage, that nominal difference will have no effect on your heating and cooling bills.
“The tiny impact that this would make on energy consumption means it would take you decades to realize any return on your investment,” says Chris Laumer-Giddens, who is chief design officer for Energy VanGuard, which is a home-energy rating, consulting and design company.
And before you reach for the phone to call a technician to add heating and cooling equipment to your garage, experts tell us that you should think twice.
“Every time you open a garage door, you’re letting so much of the inside air out and the outside air in, that you’re essentially starting from zero all over again,” Laumer-Giddens says, adding that the energy that must be expended to overcome these losses can be enormous.