Potential Influence of Moisture Sorption and Desorption of Walls on SpaceConditioning Load of Residential Buildings

The hygrothermal performance of houses isrecently being required to indicatequantitatively due to the encouragement ofenergy conservation. Several calculationmethods are practically proposed to evaluateenergy saving measures of houses. However,those methods do not take into account moisturetransfer in wall assemblies. Humiditycalculation is simply affected by ventilation andfocuses on just the building spaces. In this paper,the potential influence of moisture sorption anddesorption of walls on space conditioning loadis evaluated in several regions where the climateconditions are distributed from cold toseasonally sultry in Japan. The dynamicsimulation software based upon detailedphysical models on heat and moisture transferand airflow, which can predict the hygrotherinalenvironment of whole buildings based whetheror not moisture sorption and desorption of wallsare taken into account, is utilized forcomparative numerical experiments. Then it isclarified that the calculation error accounts toover 10 percent both heating and cooling of thetotal heat load. The influence of moisturesorption and desorption of walls is unable todisregard to predict the space conditioning load.