Membranes Improve Insulation Efficiency

Abstract

It has been determined from extensive tests involving test models and home attics that loose fill and fiber batt insulation does not function as expected by the industry. The reason for this deficiency is current test methods do not accurately predict the magnitude of air infiltration into fiber insulation as used in home attics, radiant heat infiltration into the insulation during summer, or radiant heat loss through the insulation during winter conditions. The use of (1) moisture permeable membranes over the insulation, and (2) layered membranes between fiber batts to form closed cells in the insulation both dramatically improve the efficiency of the fiber insulation. The efficiency of this insulation will be improved to an even greater degree if these membranes reflect radiant heat as well as reduce convection air currents. Extensive tests have also been conducted which show that if moisture permeable membranes are used over fiber insulation, the moisture content of the insulation will be reduced.