Series of thermal transmission tests were conducted on large wall specimens, which measured 300 by 400 cm (118 by 157 in.), using a calibrated hot box test apparatus. The wall specimens were constructed with metal framing members and were insulated with various combinations of materials.
Wall constructions were tested with and without batt insulation in the wall cavity in an attempt to determine the effect of the metal framing members on the thermal performance of the batts. In addition, the same wall specimens incorporated either wood fiberboard or extruded, expanded polystyrene (XEPS) foam sheathing to examine the effect of the metal framing members on the thermal performance of the sheathing.
The resistance values for the various wall constructions were measured at four different mean temperatures. The test results indicated that the metal framing members significantly reduced the effectiveness of the batt insulation and, to a lesser extent, the effectiveness of the sheathing. However, the batt insulation installed was slightly undersized in the width dimension and did not fill the entire wall cavity. As a result, the effect of the metal framing members on the thermal performance of the batts could not be accurately determined. R-values were calculated for the metal frame wall constructions using several analytical procedures. Some of the calculated values were in reasonably good agreement with the measured values.