Positioning And Design Recommendations For Materials Of Efficient Thermal Storage Mass In Passive Buildings

Abstract

The role of mass in energy storage has long been a subject of interest in passive buildings. Thermal mass is used to diminish temperature variations for interior spaces in desert or semi- desert climates. Energy from solar and internal gains during the day in winter is often greater than daytime heating requirements. This energy can be stored in materials within the building, and released at night to offset building heat loss. In a similar manner, building mass may allow the interior to remain cooler during the daytime in summer and reduce air conditioning requirements. In this paper, the geometric and energetic positioning of thermal mass has been studied in order to determine most convenient locations. It is found that floors receive direct solar energy for a high percentage of time, usually 70%-90% of the radiation transmitted through the window during the day (9 am to 3 pm solar time). The materials related to the technical efficiency of thermal mass are reviewed specifying the thickness most suitable for storing solar heat in the winter or keeping the interior cool in summer.