Do Insulated Garage Doors Make a Difference?

Test

• Put your hand on a metal or plastic garage door when the sun is shining on the door. If the door feels hot, the heat is transferring into the garage just as heat transfers through a metal skillet to cook food. On a hot day, a garage door absorbs heat and temperature rises inside the garage. Conversely, put your hand on a bare metal door in winter and you can feel the cold radiating through the door to chill the garage interior. Put a piece of rigid foam insulation in one panel and feel the temperature difference between the two panels.

Energy

• An insulated garage door saves energy by keeping the garage warmer in winter and cooler in summer. Without insulation, the door directly transmits heat and cold into the garage and, through house walls or common attic space, to the house. A moderate garage temperature cushions the house against abrupt temperature changes. Additionally, it prevents hot or cold air from rushing into the house when an interior garage door opens. Garage workshops are more comfortable and require less auxiliary heating in winter or cooling in summer.

Retrofit

• Insulated doors, standard or custom, fit most garages. When a door must be replaced, an insulated door may be an energy-efficient option. Many homes have metal doors without insulation that can be quickly insulated. Precut insulation kits, available at home improvement centers to fit single and double doors, typically are rigid foam panels that easily fit into the door sections. When trimming is necessary, the panels are cut with a knife or utility saw. When precut rigid foam kits are not available, cut large foam sheets to fit the door. A foam panel faced with foil is more effective, as the foil is a reflective barrier to heat and moisture. Alternative reflective barriers include foil-coated kraft paper, bubble wrap or cardboard. These barriers can be cut to size and usually need installation with tape, clips or other fasteners to keep them inside the door panels.

Tips

• An insulated garage door makes little difference if the garage walls and ceiling are not insulated. On an insulated garage, adding insulation to the door can keep the garage about 30 degrees cooler in summer and warmer in winter. Rigid foam panels fit most garage doors and block noise and vibration. Because they add door weight, automatic garage door openers may need adjustments. Check the opener manual or manufacturer's instructions for directions. Insulated panels reinforce thin door panels and may help prevent door twisting and flexing.