Phase change materials

PCM (phase change materials) is an innovative technology and an effective method for improving the thermal mass of buildings owing to it possesses the property of large thermal capacity within a limited temperature range, which is similar to an isothermal energy tank. However, most of the previous studies focused on the combination of PCM and walls that the utilization potential of rooftop is lack of concern though there is a significant amount of heat gains from rooftop.

One-year monitoring results of environmental conditions in a UK seminar room where the Cool-phase® ventilation and PCM battery system has been installed indicate thermal comfort and good indoor air quality throughout the year. CFD analysis indicates that air temperature and air distribution is uniform at occupants’ level.

Night sky radiative cooling technology using PhotoVoltaic/Thermal panels (PVT) and night time ventilation have been studied both by means of simulations and experiments to evaluate their potential and to validate the created simulation model used to describe it. An experimental setup has been constructed at the Technical University of Denmark, where the outside PVT panels are connected through a storage tank to in-room radiant ceiling panels. The radiant ceiling panels include phase change material (PCM) and embedded pipes for circulating water.

Cold storage is a way to deal with peak cooling loads. Cold storage integrated with building structures is independent of the approach used for building cooling – it can be used with passive cooling as well as mechanical cooling. High thermal storage capacity in a narrow temperature interval makes phase change materials (PCMs) a suitable medium for cold storage in built environments. A set of experiments was performed with the aim to investigate performance of PCM cold storage in building structures under various ventilation strategies.

Important properties of the indoor air quality are temperature and humidity. Very often in new and oldbuildings the temperature is too high or varies too strongly. A suspended ceiling with phase changematerials has a good influence to avoid too high indoor air temperatures. An additional heat exchangerat the outside of the building can increase the efficiency of the system by working in the night andcooling down the phase change material, so that after this cooling the full heat storage capacity isattainable.