Moisture induced changes in the building physics parameters of insulation materials

Abstract

In recent years measurements and calculations of the thermal properties of building physics parameters of materials have become very important for thermal sizing and designing buildings. Moisture is an essential factor to consider when designing and applying building materials. This article investigates the influence of moisture in building physical properties of insulating materials. Thermal insulating of buildings is sorely needed regarding energy as well as saving money. This article presents calculations for the changes in the most important building physics parameters of insulation materials influenced by water after measuring their thermal conductivity, moisture content, and density. Furthermore, this article will also present the positive or negative effects of water. Three different types of polystyrene (expanded, graphite doped expanded, extruded), mineral and glass wool fibers, as well as gypsum boards were tested. The non-equilibrium sorption behavior of the expanded polystyrene materials was achieved in a type Climacell 111 climatic chamber after drying them in a type Venticell 111 desiccating apparatus. The relative humidity varied from 25% to 90% at 293 K for 240 min. The thermal conductivity of each sample was determined by using a Holometrix 2000 heat flow meter after drying the samples to changeless weight in the above mentioned desiccating apparatus.