With the cost of living rising and winter on its way, now is a good time to examine your home and look for ways to save energy. Many repairs are inexpensive and pay off quickly. If you are willing to do a little measuring and investigating, a program on the Internet, Home Energy Saver by Lawrence Berkeley National Laboratory, will calculate cost savings produced by various improvements and reveal which ones will pay for themselves most quickly. The Idaho Power website has good advice on selecting energy-saving appliances.
Checking For Air Leaks
No amount of insulation or triple-pane windows can make up for heat loss due to air leaks between the inside and outside of the house. Air leaks need to be fixed first.
On the outside of the house, inspect every place where two different materials meet. Examine all door and window frames. Shut doors and windows on a piece of paper. If you can pull the paper out without tearing it, you have a leak. Try this with refrigerators and freezers, too.
Examine electrical and gas service entrances, outdoor water faucets and where dryer vents or cable lines pass through foundation walls.
Inside the house, hold an incense stick or lighted candle along the edges of windows and doors. Drifting smoke or a flickering candle indicates an area that needs to be sealed or insulated.
Look for broken or loose windowpanes and sashes; holes in walls, floors, and roof; cracks in the foundation; heat leaks between living areas and garage or utility room; and loose fireplace damper. Do you close the damper when the fireplace is not in use? Does the fireplace have a set of air-tight glass doors?
Adding Insulation to an Existing Home
Unless your home was specially constructed for energy efficiency, you can usually reduce your energy bills by adding more insulation. Many older homes have less insulation than homes built today, but adding insulation to a newer home may also pay for itself within a few years.
To determine whether you should add insulation, you first need to find out how much insulation you already have in your home and where.
You will need to find out the following:
Where your home is, isn’t, and/or should be insulated
What type of insulation you have
The R-value and the thickness or depth (inches) of the insulation you have.
If you live in a newer house, you can probably find out this information from the builder. If you live in an older house, you’ll need to inspect the insulation yourself.
Inspecting and Evaluating Your Insulation
Check the attic, walls, and floors adjacent to an unheated space, like a garage or basement. The structural elements are usually exposed in these areas, which makes it easy to see what type of insulation you have and to measure its depth or thickness.
Loose fibers, yellow, pink, or white, are probably fiberglass. Measure the depth in inches and mulitiply by 2.5 to get the R-value.
Loose fibers that are dense gray or nearly white, sometimes with black specks, are probably rock wool (which is not a form of asbestos!). Measure the depth in inches and mulitiply by 2.8 to get the R-value.
Loose small gray flat pieces or fibers are most likely ground up newsprint. Measure the depth in inches and mulitiply by 3.7 to get the R-value.
Lightweight granular material is probably perlite or vermiculite. Measure the depth in inches and mulitiply by 2.7 to get the R-value.
Batts of loosely woven fibers, yellow, pink, or white, are fiberglass. Measure the thickness in inches and mulitiply by 3.2 to get the R-value.
Inspect the exterior walls using an electrical outlet.
Turn off the power to the outlet. Remove the outlet cover and shine a flashlight into the crack around the outlet box. You should be able to see if there is insulation in the wall and possibly how thick it is. Pull out a small amount of insulation if needed to help determine the type of insulation. Check outlets on the first and upper floors, if any, and in old and new parts of a house. Just because you find insulation in one wall doesn’t mean that it’s everywhere in the house.
Inspect and measure the thickness of any insulation in unfinished basement ceilings and walls, or above crawl spaces. If the crawl space isn’t ventilated, it may have insulation in the perimeter wall. If your house is relatively new, it may have been built with insulation outside the basement or foundation walls. If so, the insulation in these spaces won’t be visible. The builder or the original homeowner might be able to tell you if exterior insulation was used.
Determining Recommended R-Values
When you find out the R-values of your insulation, you can then use your Zip Code and the U.S. Department of Energy’s EERE* website to determine how much insulation you should add and where to achieve the recommended insulation levels for maximum energy efficiency. Look for the R-value calculator from Oak Ridge Laboratory on the EERE site. This website also gives information on the types of insulation available for remodeling and new construction.
*Energy Efficiency and Renewable Energy
Recommended R-Values for Boise
Exterior wall, insulation blown in between studs R13
Floor, if crawl space is vented R30
Crawl space wall, if unvented and floor is not insulated R25
Basement wall interior, studs, fiberglass, and sheetrock over concrete R11
Exterior insulating sheathing or foamboard beneath siding or veneer R5
U.S. Department of Energy and Almanac Staff