The purpose of insulation can be stated simply: to keep the heat or cool where you want it.
Most insulating materials create “dead-air spaces.” Since heated or cooled air want to move quickly, these dead-air spaces slow down that air and it takes longer for the warm or cool air to mingle with the colder (or warmer) air outside.
What you’re after is to keep the cold or hot air from getting in you house, and to stop the warm or cool air from getting out through the walls or roof. In new home construction, full insulation of walls, attic or roof is easy. In your existing home, insulating may be more difficult, but you probably can reach some of the important places.
It’s important to keep the dead-air in mind. It’s like the fishnet long johns that are worn by arctic explorers, or down jackets worn in northern climates. They will keep the body warmer than layers of solid clothing.
Good heat conductors are poor insulators. For example, a stone outer wall is poor in insulation value. The same can be said for brick and concrete. Sheet metal (for the so-called tin roof), single-pane glass, stucco and roofing shingles all fall into the same category: very little insulation value.
Lumber, composition board, and earth walls have some insulation value, but the real winners are the expanded glass and mineral fibers you can buy as fiberglass, newspaper products like cellulose, or rigid foam boards.
Crumpled paper and dry straw also can serve that air-trapping purpose, but are a fire hazard and should be used. Dry paper can catch fire even though it is encased in a tightly sealed box made of steel a quarter-inch thick.
A thorough job of insulating your attic, walls, and floor can save up to 50 percent on the winter and high summer fuel bills, so we’re talking about the major item in this business saving energy. The cheerful thing about this undertaking is that every step is profit. Even if you don’t accomplish everything, each insulation area check off on your list will be a money saver.
This up-coming week will deal with steps for increasing insulation in an existing home.
Taken in part from 547 Tips for $aving Energy in Your Home by Roger Albright