Study on PCM Application in Old Building Energy Efficiency

Use PCM is a way to store thermal energy on reducing the material volume and in building applications to choose the desirable phase-change temperature to reach a thermal comfort temperature. For old buildings, it is impossible to use traditional PCM as the envelope. But using a piece of PCM as a part of window maybe is a feasible choice. We have done experiments to study the PCM effects about indoor temperature and density of heat flow in Shanghai, China. The results of these experiments indicated the indoor average temperature decreased 1.67°C in the daytime and increased 1.71°C in the night, the space heat gain decreased 61% in the daytime and increased 230% in the night when PCM had used in the experimental rooms. The heat flow of PCM is the half of the glass windows in the daytime. PCM would decrease the indoor heat load in the daytime and change the thermal indoor environment in the evening. The investment payoff period is about 4 years.