Phasenwechselmaterial im Metallleichtbau zur Optimierung von Energieeffizienz und sommerlicher Raumtemperatur

Phase change material for lightweight metal constructions to optimize energy efficiency and the indoor temperature in summertime.

In wintertime, for insulated metal claddings very good solutions do exist that minimize heat transfer yielding to very low U-values with at the same time very low cross-sectional depth. In summertime however, due to a lack of mass, these cladding systems reveal a significant shortcoming as no storage of heat is possible that would keep the indoor temperature on an acceptable value.
This effect is of importance even for moderate climate zones like middle Europe. If it would be possible to buffer the surplus of heat (occurring during the day like solar gains and internal heat sources) in the surrounding walls and floors and to recharge these elements during nighttime, energy consuming air-conditioning can be avoided. But buffering of heat normally necessitates a certain amount of storage mass that for light-weight structures is not available. Due to special phase change materials (PCM) with a melting temperature in the range of the targeted room temperature, a considerably high quasi-heat storage capability can be achieved, that results from the enthalpy in the transition from solid to liquid.
Already relatively small amounts of PCM are able to produce a significant effect considering the very light structure. Thereby the temperature behavior during summer will be clearly improved as well as the energy demand will be reduced. The following contribution shows the basic principle, technical solutions as well as experimental results, which yield into comfortable and energy saving buildings with metal claddings.