Heat and Moisture Transfer in Wood-Based Wall Construction: Measured versusPredicted

摘要

This report describes a comprehensive laboratory study to verify the accuracy ofMOIST for 12 different wall specimens. The rate of heat transfer through each of the 12 wall specimens was measured. The moisture content of the exterior construction materials was measured for eight of the twelve wall specimens. For the remaining four walls, the relative humidity level was measured at the interior side of the exterior sheathing. The measured heat transfer rates, moisture content levels and relative humidities were compared to the predictions of MOIST. In general, the agreement between MOIST and the experimental measurements was good. The moisture content predicted by MOIST was within one percent of the measured values for seven of the eight walls that contained moisture content sensors. The measured relative humidities for two of the remaining four walls agreed well with the MOIST predictions. The relative humidity measurements from the other two walls could not be compared to MOIST since the walls were constructed with vapor retarder defects that introduced two-dimensional effects. The heat flux predicted by MOIST was within ten percent of the values measured under steady-state conditions.