November 30, 2011


Historically, weatherization programs have required that cellulose insulation materials be dense-packed to a minimum installed density of 3.5 pcf. This density limit was, in part, required to realize beneficial reductions in air leakage. The Building Performance Institute (BPI) currently has under development two standards that will set requirements for the airflow resistance of insulations used in retrofit cavity (i.e. dense-pack) installations and define acceptable test methods to measure the airflow resistance of insulation materials used in dense-pack applications. An experimental apparatus and test method were developed for the purpose of measuring the airflow resistance of dense-packed fiber insulation installed as a retrofit to empty wood-frame wall cavities.