A Basic Study of Heat Transfer Through Foam Insulation

the development of improved foam insulations has been an evolutionary process. Current research efforts to develop higher R value foams are handicapped by the fact that the mechanisms of heat transfer through foam are not well understood and a basic model is not available. It is the goal of this paper to help develop a better understanding of the mechanisms controlling heat transfer through foams. This will aid future foam developments and form the basis of a fundamental model for the R value of foam. This work also applies to understanding the aging of foams. In a review of the foam literature, Valenzuela [1] showed that published heat transfer models underestimate the effective conductivity of foams, even when upper limits are used for the contribution of solid and gas conduction. Gas convection within the cells was shown to be negligible and hence could not account for the discrepancy. It was hypothesized that thermal radiation accounted for the balance of