Reduced-scale experiments on the thermal performance of phase change material wallboard in different climate conditions

Integrating phase change material (PCM) into building envelope is an effective approach for establishing a comfortable indoor thermal environment in the summer. The full exploitation of thermal storage performance of PCM envelope depends on the suitability of the outdoor climate conditions. There is one key question should be solved: How to quantitatively describe the effects of local climate characteristics on the thermal storage performance of PCM envelope? Thus, in the present study, the thermal storage performance of PCM wallboard is investigated under different climate conditions in reduced-scale experiments with artificially controlled conditions. The typical meteorological year in 10 cities in Northern and Western China are determined to extract the experimental conditions. Based on the degree hours concept, evaluation indices are developed to quantitatively analyze the climate characteristics, including the accumulative temperature during a whole day and the accumulated temperature difference between the outdoor air temperature and phase change temperature. The combined effect of the range of variation in the temperature and the accumulated temperature are obtained base on the indices. Reductions in the accumulated temperature of over 88% are observed under the climate conditions in Xi'an and Kashi. However, the reduction is only 36.8% under the condition in Xining. Finally, with nonlinear regression analysis. The relationship between the thermal storage effect of PCM wallboard and the accumulated temperature difference is determined by nonlinear regression analysis. The results provide a reference to assess the suitability and appropriate thermal design for PCM envelope in different climate conditions.