R-Values
R-value is a measure of how well the insulation slows heat flow. The
larger the R-value, the more effective the insulation and the less heat
flow. Each wall, ceiling, and crawl space in the home may have a
different R-value. The U.S. Department of Energy Web site contains a
computer model that suggests R-values while taking into account
specific home factors, such as efficiency of air conditioning equipment.