Thermal comfort in a building with Trombe wall integrated with phase change materials in hot summer and cold winter region without air conditioning

Abstract

Trombe wall and phase change materials (PCMs) are two effective ways to regulate indoor thermal comfort. However, Trombe wall surfers from overheating in summer and PCMs suffer from low heat transfer rate caused by the limited thermal conductivity. To compensate the shortcomings of the two methods, this paper proposed a Trombe wall system integrated with PCMs. Based on a light-weight building envelope in Changsha, China, the thermal comfort of 10 kinds of Trombe wall systems with PCMs with a melting temperature of 18–28 ℃ were studied. Taking the integrated indoor discomfort duration (ID), integrated indoor discomfort degree-hour (IDH), indoor air temperature (Tin), PCM liquid fraction (γ) and heat flux across wall (q) as evaluation indexes, the indoor thermal comfort was assessed in hot summer and cold winter region. Results show that the Trombe wall helped PCMs complete the phase change process effectively. Trombe wall with PCM25 next to the wall inner surface possessed the lowest annual ID and IDH, as 2877 h and 12,974 ℃· h, respectively. Compared with the values in a traditional building, the ID and IDH were reduced by 7.01% and 14.14%. In order to give full play to the heat storage and heat release of the Trombe wall with PCMs, PCMs with phase change temperature 7℃ lower than the peak ambient temperature in summer or 8℃ higher than the winter night temperature was recommended according to regional climate conditions.

Keywords

• Trombe wall
• Phase change materials
• Integrated indoor discomfort duration
• Integrated discomfort degree-hour
• Liquid fraction