What are the R Values and Effectiveness of Cellulose Building Insulation?
The thermal resistance or heat-loss resistance of cellulose insulation sold by Pal-O-Pak Insulation company, for a 10-inch depth, was reported as 0.635 per square meter. The product heat resistance ranged (by thickness) from 0.004 to 1.602 m2· K· W-1. Modern blown-in cellulose building insulation has an R-value of about 3.70 per inch. What these data and most reports of insulation products’ resistance to heat loss do not include is the large impact on building heat loss of the degree of care with which any insulating product has been installed. Gaps between insulating materials and building surfaces can permit drafts which can overcome otherwise high “R” values that may be associated with the insulating material. (Just imagine a well-insulated home in the dead of winter but with a few windows open.) Insulating materials that by their physical nature tend to fill in cracks and gaps without much human effort, such as blown-in products or foamed products, are likely to produce fewer air l
