Use of a whole building heat and moisture transfer building simulation tool to evaluate moisture buffering capacity of clay plasters in hot-humid climates

Studies on hygrothermal properties of materials to passively moderate indoor humidity levels has in cold-moderate climates conclude that it helps improve Indoor Air Quality and reduce auxiliary energy loads. This research uses a validated whole building Heat And Moisture transfer energy simulation tool (WUFI Plus) to study the effect of a selected hygroscopic clay plaster on indoor environment in hot-humid climatic condition. A reference scenario was defined with use of gypsum plaster as the common wall finishing. Results indicate that clay can help buffer indoor RH especially when high indoor RHs happen. However, the effect on indoor temperatures is negligible. Results also indicate the importance of taking moisture into account in building energy calculations.