Air Infiltration

Cocoon® insulation demonstrates proven superiority in reducing air infiltration over other types of insulation. The reasons are simple:

• Cocoon is two to three times denser so it effectively blocks air better than lightweight fiberglass batts

• Cocoon completely fills cavities, eliminating voids and gaps which are common with batt installations that can lead to convective heat loss

In another side-by-side test, the Leominster, MA Housing Project for the Elderly found that thermally equivalent cellulose insulated buildings have an effective leakage area 40% lower than similarly constructed buildings insulated with R-13 fiberglass batts in the walls and R-38 fiberglass batts in the ceiling.

According to test results at Oak Ridge National Laboratory, cellulose insulation maintains its R-value over a full range of temperatures, while leading brands of loose-fill fiberglass lose up to 50% of their R-value in cold temperatures.

When Cocoon 's high thermal performance is added to its value for effective air infiltration control, the result is an insulation system that outperforms fiberglass batts by a significant margin.

In May 1994, Energy Design Update addressed the issue of vapor retarder use with dry blown-in cellulose. From a building science point of view there are two reasons to eliminate the vapor retarder. "Except for homes in very cold climates that will have high indoor humidity levels for long periods of time, a poly vapor retarder is probably not necessary as long as the wall is airtight and the drywall is painted. More important, for homes in warm climates an interior vapor retarder may actually cause moisture problems in summer."

In a review of MIMS Insulation Facts #14, "Spray and Wet-blown Insulation Systems," David Yarbrough and Ronald Graves, of R&D Services, write "The material density of spray and wet-blown insulations are generally higher than those of factory-made batts. Air does not move as easily through the high density insulations as it does through the low density insulations. Air movement through and around cavity insulation generally reduces its effectiveness. Air infiltration around windows, doors, and plates is admittedly a major factor. Air movement through and around cavity insulation is also a factor."

In an article dated October 1991 in Energy Design Update, tests performed at the University of Illinois and Oak Ridge National Laboratory (ORNL) show that loose-fill fiberglass suffers performance degradation when temperatures drop below 30 degrees F. "Below that point, the heat loss increased geometrically with temperature difference, indicating a loss of effective R-value. At a temperature of 10 degrees F, the effective R-value dropped over 50%." After the initial tests on fiberglass were released, the Cellulose Industry Standards Enforcement Program (CISEP) in November 1991, hired ORNL to run a series of tests on cellulose. The results showed no decline in R-value using cellulose insulation.