from Kay in Eau Claire, WI:
#289
I recently heard a promotion about an aluminum/reflective sheeting insulation product that reflects heat away from the home in the summer and back into the home in the winter. Can you tell me if this is a good type of insulation to install in my home?
Proper air sealing & insulation may be a better option.
Reflective insulation systems are fabricated from aluminum foils with a variety of backings such as kraft paper, plastic film, polyethylene bubbles, or cardboard. Reflective insulation is generally most effective in reducing downward heat flow (which means it’s better at keeping heat out of your house in the summer vs warmth in your house in the winter). Reflective systems are typically located between roof rafters, floor joists, or wall studs. If a single reflective surface is used alone and faces an open space, such as an attic, it is called a radiant barrier. Radiant barriers are sometimes used in buildings to reduce summer heat gain and winter heat loss.
Reflective insulation is an example of a product that is more effective in hot climates than in cool climates (like Wisconsin), when installed correctly (e.g. the installation of this material may cause existing insulation to be trampled, if the installers are not careful). It is important to note that this reflective foil, when facing upward, may gather dust, which could likely reduce its effectiveness. Additionally, for what many of these types of companies charge to install reflective insulation systems, homeowners in Wisconsin could likely spend less on proper air sealing and insulation and make a larger impact on reducing their energy bills, as well as make their home more comfortable. Consider having in-home evaluation with a Home Performance with ENERGY STAR® consultant. It’s like a check-up for your home and can help you identify the most cost-effective solutions for your home. For more information you might want to check out the answer to another Wisconsite's question on what an energy evaluation is.
No matter what kind of insulation you buy, check the information on the product label to make sure that the product is suitable for the intended application. A good insulation label should have a clearly stated R-value (indicates insulation's resistance to heat flow), and information about health and safety issues. An informative label should state:
- The type of insulation material;
- The R-value (and test method of determining R-value);
- The types of spaces that can be insulated;
- Safety precautions in application and use, including any fire-hazard related restrictions;
- The quantity in the package; and
- The name and address of the manufacturer or distributor.
For more information about the types of insulation available, visit the U.S. Department of Energy's Energy Savers Web site.
Published Tuesday, June 09, 2009