Spray Foam Insulation Outperforms Fiberglass

What is this guide about?

SPFA contracted with R&D Services to test low density, waterblown SPF and 2lb density HFC 245fa blown insulation systems in an attic thermal performance climate simulator at Oak Ridge National Laboratories. The SPF assemblies were compared to a typical blown-in fiberglass insulation attic application.

Oak Ridge National Laboratory is the largest US Department of Energy science and energy laboratory, conducting basic and applied research to deliver transformative solutions to compelling problems in energy and security.

Insulation Systems Tested

Three attic insulation systems were tested in the LSCS for both Winter and Summer conditions. The thermal test section has dimensions 8x8 ft. and area of 64 ft.

• Loose-fill fiberglass on floor of attic (depth 14 in.)
• Low-density foam between rafters on the underside of the roof deck (depth 5.5 in.)
• Medium (2. lb) density foam between rafter on the underside of the roof deck (depth 4.0 in.)

Test Results Comparing Fiberglass vs Spray Foam Insulation

The tests results demonstrate that both low density and medium (2 lb) density SPF installed to the underside of the roof deck in attic assemblies maintain a much higher effective R-value at both low and high temperatures than the fiberglass insulation system. The SPF systems maintained 74% and 83% respectively of reported R-value at low outside temperatures compared to 46% for the fiberglass assembly, and 61% and 67% of reported R-value at high outside temperature compared to 51% for the fiberglass assembly.

More information on spray foam insulation can be found on the Oak Ridge Nation Labratory website.