Upgrading a Door to Save Energy

Published by: Paul Batchie, pbpublic@gmail.com
Published on: 2010-01-10 15:26:13

As wonderful as our Connecticut houses are, they wouldn't be of much use if we couldn't get in them. And so, at some point a very long time ago, someone invented the door. Consider what we ask the door to do. A good door will keep out extremes of temperature, the wind and the elements. It will keep out unwanted intruders, of either the two- or four-legged variety. But we also expect the door to let us into and out of the house when we want, quickly and with ease, and we often want to be able to see through the door, to enhance our view and to qualify visitors. And because the door is very often the focal point of the house exterior, we of course want it to be attractive.

Because of the ever-increasing cost of energy, the aspect of doors that has received the most attention over the last thirty years has been their insulating properties. Wood, the standard material for doors for millennia, is thankfully a good insulator, but doors with foam cores have become popular since the first energy crisis back in 1973. This is for good reason. COEnergy assigns the following R values to doors made of various materials (R value is a measure of resistance to heat flow; the higher the value, the better the insulating value of the material):

1-¾" Wood panel door: 1.85
1-¾" Wood solid flush door: 3.03
2' Steel door with foam: 15

The steel door number is going to be a little high because most residential doors are only1-¾" thick, but even so, a foam-filled door's R-value should be a factor of seven over that of a standard wood panel door.

Steel doors are very useful and cost-effective, and manufacturers have made them appealing to the eye by embossing them to look like panel doors, applying decorative moldings, and adding glass. For most situations, the steel door is more than adequate aesthetically. Some homeowners, however, especially those who want a stained-wood look rather than the paint-grade look that steel doors offer, are looking for a more enhanced appearance. Manufacturers have responded to this upscale demand by making doors similar in construction to steel doors, but with stainable fiberglass skins.

The fiberglass door is the epitome of doors because it incorporates the best features of all the materials. When stained, one will be hard-pressed to distinguish a fiberglass door from its rich-looking oak counterpart. Filled with foam, the fiberglass door offers much higher R values than wood. And because it's not dependent on traditional mortise and tenon joinery, the fiberglass door has little chance of the warpage or sagging that often characterizes wood doors over time.

Another aspect of doors that is worth considering is the use of "lights", or glass, in or around a door. Modern door glass will be high quality double-pane, and often will be filled with inert gasses and have a low-emissivity (Low-E) coating which further enhance the R value, to help keep heat loss under control. This becomes especially important as the glass area becomes large, as is the case with patio doors. If your patio doors have substandard glass, worn weatherstripping, or have lost their dry air seal, upgrading to more efficient doors will both save energy and make your home more comfortable.

Modern doors have actually become so efficient that the Department of Energy no longer recommends the use of storm doors for most new installations, and warns against their use when direct sunlight can build up inter-door temperatures.

Finally, if you have a heated garage, consider the state of its doors. Because garage doors are so large, energy loss can be very significant. Manufacturers have made the switch to foam-filled doors, and they also have improved weatherstripping to prevent drafts. Upgrading garage doors can save large amounts of energy, and doing so can at the same time often dramatically enhance a house's exterior appearance.

For a door installation contractor in Connecticut, contact us today!

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