Product Info - Thermal Cellulose vs. Fiberglass

One common question asked by both home owners and builders alike is "How does cellulose insulation performance compare to fiberglass?" To address this question we commonly refer to a study done back in July of 1990 by the National Thermal Performance Institute (NTPI), Denver, Colorado.

In this study two identical test buildings measuring 8 feet by 8feet were constructed at the University of Colorado School of Architecture and Planning. One building was insulated with 5 1/2 inches of wet-spray cellulose in the walls and R-30 loose fill cellulose in the ceiling. The other was insulated with R-19 unfaced fiberglass batts in the walls and R-30 kraft-faced batts in the ceiling. Both buildings were elcetrically heated and the energy consumption measured for a 16 day period between January 24 and February 12.

The conclusion drawn by researchers was that cellulose showed consistently lower energy consumption during the 16 day test period. The "Relative" difference in energy consumption was that the cellulose insulated building required 18 to 20 percent less energy to heat through the test period. The study also showed that when the heat was turned off during one of the winter nights that the rate of temperature decay was slower for the cellulose insulation building and remained 7 degrees Fahrenheit warmer by morning.

An important conclusion that can be drawn from this study is that energy efficiency goes beyond steady state heat flow measurements taken in a laboratory. To be a truly effective insulation it must not only have a high R-value but also be resistant to convective air movement and air infiltration.

The bottom line is that Weathershield insulation provides better all around protection which translates to lower energy costs and a more comfortable living environment.

References:

Energy Design Update, Research and Ideas "Cellulose Versus Fiberglass - Side-By-Side Tests", Cutter Information Corp., Arlington, MA, July 1990

Proceedings from 1990 EEBA conference, Energy Efficient Building Association, University of Southern Maine, Gorham, ME.