Latent heat loads due to moisture transmission through envelope parts can contribute substantially to the overall energy consumption. Experimental data have shown that the implication of moisture on the thermal load can be of the order of 10-15% for wall systems. The impact of moisture transport on the HVAC equipment sizing and energy consumption is quite serious, contributing to over 20% of the envelope consumption in certain climates. Material property data such as the sorption, suction isotherms and the vapor and liquid transmission properties are needed for accurate evaluation of these loads.

Principal Investigator: Mavinkal K. Kumaran, National Research Council Canada

Conducted: September 1998 - July 2002

Sponsored by: TC 4.4, Thermal Insulation and Moisture Retarders