Home Insulation

Insulation

Properly insulated homes can use 30 to 50 less energy than homes without insulation.

Lining your "thermal envelope" - adding materials that don't readily allow heat to leak through your walls, ceilings, floors, from around your home's foundations and its ductwork - saves energy by keeping heat in during the winter and keeping heat out during the summer.

The effectiveness of a piece of insulation is measured by its R-value.

The R-value in insulation designates its resistance to heat flow. The higher the R-value, the greater the insulating ability - the more effective it is.

Generally speaking, each time you double the R-value of insulation, you cut your conduction heat loss in that area in half.

Adding insulation to an uninsulated attic is the most cost-effective, energy-saving measure you can do. Most older houses were built with little or no insulation.

You can greatly increase the energy efficiency and comfort of a home by installing insulation with an R-value higher than the minimum requirements.

But to truly enjoy the benefits of insulation, it must be installed correctly.

Compressing it or leaving gaps through which air can flow can cut insulation's effectiveness in half.

When insulating your attic, it's important not to clog the attic vents under the eaves.

Keep air circulating freely above the insulation by installing baffles (typically a piece of Fiberglas batt placed several inches away from the vent).

Places to Insulate

In unfinished attic spaces, insulate between and over the floor joists to seal off living spaces below.

In finished attic rooms with or without dormer.

All exterior walls-between living spaces and unheated garages, shed roofs, or storage areas.

Floors above cold spaces, such as vented craw spaces and unheated garages.

Band joists.

Replacement or storm windows and caulk and seal around all windows and doors.

Weather-Stripping

Weather-stripping and caulking is probably the least expensive, simplest, most effective way to cut down on wasted energy in the winter and summer.

Improperly sealed homes can squander 10 to 15 percent of the homeowner's heating dollars and reduce the effectiveness of air-conditioning in the summer.

While some new doors now come with factory-applied weather-stripping, such designs are a recent innovation. Millions of doors across the country have little or no weather-stripping.

Since most doors have a space - sometimes as much as a quarter inch or more - between the bottom of the door and the floor, large amounts of air can flow in and out of the house. For a typical 36-inch entry door, a quarter-inch small crack can leak as much air as a nine-square-inch hole in the wall.