Comparing Radiant Barrier Foil, Radiant Barrier Decking and Painted Reflective Barriers in Residential Attic Applications
The official study reports the four attic configurations that were evaluated are: 1) no radiant barrier (control)
2) perforated low-e foil laminated oriented strand board (OSB) deck
3) low-E foil stapled on rafters
4) liquid applied low-emittance coating on roof deck and rafters.
All test attics used nominal fiberglass batting insulation on the attic floor.
Results indicate that the three systems with radiant barriers had heat flows through the attic floor during summer daytime condition that were 32.8%, 49.8%, and 19.1% lower than the control, respectively. Clearly indicating that foil stapled to the bottom of roof rafters has the BIGGEST impact on reducing the heat load into the attic.
49.8%
lower heat load& easier to keep cool
Note
The study was not performed in an actual residential attic, but rather in a large scale climate simulator, in order to have complete control over all conditions across the 3 scenarios they were comparing.