Numerical analysis on the thermal performance of PCM-integrated thermochromic glazing systems

Thermochromic glazing and phase-change materials are capable of adapting their optical and thermal properties in response to temperature variation, without consuming additional energy. They are therefore ideal construction materials for passive building envelopes. In this study, the energy-saving potential of combining the two materials into one adaptive glazing system is investigated numerically. Computational fluid dynamic models were constructed to simulate the thermal performance of different adaptive glazing systems consisting of the two materials. The models were tested against two existing experimental studies, and good agreements were found. Based on the models, the applicability of the novel glazing systems for a south office building façade was investigated for summer and winter in Shanghai, China. It was found that PCM-integrated thermochromic triple glazing units outperform normal double-glazing units by reducing total heat gain by up to 32% and 40% for a sunny and cloudy day in summer, respectively. In winter, however, they tend to block more desirable solar radiation and hence are not as effective as normal double-glazing units.