PO-86-12-3 -- Laboratory Measurement of Thermal Transmittance of Several Masonry Wall Systems

Thermal transmittance (U-value) for several masonry wall systems was measured in a guarded hot box in accordance with ASTM test method C236. The wall systems are block walls with and without various core insulations, cavity walls with and without cavity and core insulation, special block walls with factory-installed insulation inserts, and walls with surface mounted, rigid insulation boards. The measured U-values of the wall systems were then compared with calculated U-values based on ASHRAE procedures. In general, there was disagreement between the calculated U-values and the measured U-values. It is believed that multidimensional heat flow and the lack of knowledge of accurate values for thermal conductivities of the components contribute to the disagreement.

Units: Dual