Factors Affecting Humidity Conditions of a Face Wall Layer of a Heated Building

Abstract

Heat and humidity processes occurring in external wall of heated buildings depend mostly on external climate factors, i.e. air temperature and relative humidity, rainfall, sun radiation and conditions inside rooms. In three layer walls the face layer is specially endangered as humidity together with negative temperatures contribute to lowering its durability. Increased humidity content results in lowering insulating properties of materials which in turn leads to increasing heat consumption in a building during the heating period. In the article there are introduced results of simulations performed with WUFI ®PRO 5 software which aimed at analysing the face layer humidity changes caused by: exploitation conditions defined by 3rd and 4th class of room internal humidity, external climate influence, partition orientation. The calculation were performed for two different internal partitions drying from technological humidity during the initial five years of building exploitation. The partition in question is a three layer wall with pore ceramic 25cm thick and elevation layer of clinker brick 12cm thick. In the first variant insulation is mineral wool, in the second - styrofoam. For the particular layers of analysed partitions initial humidity content was assumed as resulting from technological conditions for building walls. The simulation let us state the technological humidity drying period of face layer, as well as humidity changes during the later period of exploitation resulting from climate influence. It was stated that elevation layer humidity condition is strictly associated with applied thermo-insulating material and partition orientation according geographic directions.