Wall-Attached Night Ventilation Combined with Phase Change Material Wallboard in Hot Summer: An Experimental Study on the Thermal Performance

Night ventilation is regarded as a promising cooling strategy by storing night cooling in the thermal mass of the building. However, night ventilation performance in hot summer is restricted by the climatic limits. In this paper, we propose a new solution as the integration of wall-attached night ventilation(WANV) and phase change material wallboard(PCMW). The principle of the proposed system is to utilize the wall-attached jet ventilation to achieve forced convection and to adopt latent energy storage of PCMW to enlarge the energy storage density capabilities, and the coupling method is expected to improve the night ventilation performance. Comparative experiments were conducted to evaluate the thermal performance of the hybrid system by evaluating indoor temperature history, thermal comfort time and cooling efficiency. Due to the high thermal energy storage density capability of PCMW, it was found that the presence of PCMW has a negative influence on night cooling efficiency but still has a positive influence on the overall cooling effect. The proposed WANV combined with the PCMW system significantly increased the temperature decrease of room air and west wall inside surface during one hour’s night ventilation by 94.97% and 67.74%, respectively, and reached an extension of 38.42% of indoor thermal comfort time. The results highlight the potential of WANV integration of PCMW to improve the thermal performance of night ventilation.