Insulation is both a property of a building and the name for material added to the structure to provide more protection from weather elements - heat and cold. A well insulated building requires less energy to heat or cool to a comfortable temperature. A secondary benefit of insulating the walls of the building is that when properly applied, it will have the effect of reducing the amount of noise transmitted.
One way of measuring the effectiveness of insulation is its R-value. The higher an R-value, the more it blocks heat transfer. Some manufacturers give an R-value; that value is dependent on correct installation. It's generally measured at a particular thickness, since increasing the thickness will usually increase the insulation.
When calculating the R-value of insulation, it's also important to consider the overall condition of the material being used. For example, fiberglass insulation will lose much of its stated R-value if compacted, wet, moldy, or dirty (such as when it has long-term exposure to a leak from an air duct). The insulation must also be installed in a continuous sheet -- if not, then heat and possibly air movement may still occur around its edges, through condctive metal that passes from one end of the insulation to the other, or through other compromising situations.
MaterialsEditSome of the materials used for insulation are
Just about any object provides some insulation, but some materials provide much better insulation than others. However, some materials, such as aluminum, will conduct heat rather than retain it.
Many good insulators are dangerous or toxic, so please be careful when using and handling them. Other materials, such as fiberglass, can be a skin irritant, and while touching them is not dangerous, it is preferable to avoid it.
- air conditioning
- energy efficiency
- spot insulation
- window film
- ENERGY STAR on Air Seal and Insulate with ENERGY STAR
- Energy Savers from the U.S. Department of Energy on Adding Insulation to an Existing Home
- North American Insulation Manufacturer's Association (NAIMA)
- Natural Home & Garden on The Best Insulation Types for Your Home
- Bonded Logic Inc. (commercial site, cotton and cellulose insulation)
- U.S. Department of Energy Fact Sheet on Insulation
- Wikipedia's article on R-value (insulation)