Has the Oak Ridge study on convective heat loss in blown fiberglass been updated to cover newer materials?
I'm evaluating blown cellulose vs. blown fiberglass (Knauf Ecofill). The Oak Ridge study is often quoted regarding the drop in R-value of blown fiberglass when the temperature differential is high. However the tested fiberglass density (.4 - 5 lb/ft^3) is much lower than the newer fiberglass. Also, for what it's worth (maybe nothing), Knauf states that "When tested against three cellulose products using ASTM C 522, EcoFill Wx showed 20 to 100% better air flow resistance than three leading brands." That's an acoustic test, though, maybe not applicable to convection.
Anyway, the bottom line is: has anyone updated the ORNL test with newer blown fiberglass? The ORNL site itself doesn't seem to mention that test anymore, and says nothing bad about blown fiberglass in its various insulation-related papers.
Posted Jul 21, 2014 8:51 PM ET
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