Research on the phase change materials for the passive solar house in Tibet

Thermal energy storage can be accomplished either by using sensible heat storage or latent heat storage. Energy storage in the walls, ceiling and floor of buildings may be enhanced by encapsulating suitable phase change material (PCMs) within these surfaces to capture solar energy directly and increase human comfort by decreasing the frequency of internal air temperature swings and maintaining the temperature closer to the desired temperature for a longer period of time. The indoor temperature has been numerically evaluated in a passive solar building in Tibet with PCM by using energyplus. Effects of the melting temperature and phase transition zone of the PCM are analyzed. The results show that: (1) the passive solar heating in Tibet is very efficient; (2) in Tibet, the optimal melting temperature of PCMs is about 19°C; (3) PCM composites with a wide phase transition zone provides better thermal performance; (4) the PCM effectively shaves the temperature swing by 54.2%; (5) the PCM makes the maximum indoor temperature to postpone 1 hour in December.