from Norm in Fremont, WI:
#440
I currently have about 7 inches of cellulose insulation in my ceiling joists of a two-story home. How much and what type of insulation should be added to get the maximum economic benefit?
Insulate attics to a minimum of R-50.
Our recommendation is to insulate attics to a minimum of R-50 (or maximum allowable depth) if the existing R-value is R-30 or less. Your current R-value is about R-26 (based on 7” of cellulose @ R-3.7 per inch). We would recommend adding blown-in cellulose to reach that R-50 (or greater) level.
Give serious consideration to air sealing the floor of the attic prior to adding more insulation. Depending on the age and style of your home, and the number and sizes of penetrations through the attic floor plane, anywhere from 10 percent to 40 percent of your heat energy is being lost to the unconditioned attic and ultimately to the exterior. To find out how leaky your home is and where those air leaks are, you should consider having an in-home evaluation with a Home Performance with ENERGY STAR® consultant. They will conduct a conduct a blower door test to reveal those air leaks, as well as a thorough inspection of all the systems in your home and identify opportunities to improve your energy efficiency and lower energy costs. You'll receive a written report of the findings and a list of recommended solutions. That way you can compare the potential savings, cost and Cash-Back Rewards associated with each of the recommendations.
Published Wednesday, September 02, 2009