Thermal performance analysis of lightweight phase change envelopes

To improve indoor thermal comfort and achieve building energy saving, a new envelope structure based on phase change material (PCM) was proposed. Firstly, an experimental platform was built around the room model, and the effects of ambient temperatures and PCM layout on the room temperature at different times were explored. Subsequently, a room numerical model heat transfer was constructed and the experimental verification was completed. The effects of PCM thickness, position, arrangement, and melting point difference on the room temperature at each time were analyzed based on the latent heat utilization rate, temperature fluctuation amplitude, and delay time. The experimental results show that when the walls all around the room contain PCM, the maximum indoor temperature can drop to 29.5 degrees C, and the maximum temperature drop is 3.2 degrees C. In addition, the greater the heat flow, the less effective the PCM is at controlling the temperature in the room. The simulation results show that when the PCM with a thickness of 15 mm is placed on the interior side of the wall, the maximum indoor temperature can be reduced to 29 degrees C, the maximum temperature drop is 2.9 degrees C, and the peak indoor temperature is extended by 0.8 h. When the PCM is arranged in series and the melting point difference is 3 K, the temperature control effect is the best, the maximum indoor temperature can be reduced to 25.7 degrees C, the maximum temperature drop is 2.9 degrees C, and the temperature fluctuation is the minimum, 2.6 degrees C.