Taking benefits of using PCMs in buildings to meet energy efficiency criteria in net zero by 2050

Considering the share of 40% and 35% of buildings in energy consumption as well as CO 2 emissions, adding phase change materials (PCMs) is an effective technique to tackle high energy demand and considerable CO 2 emissions. When PCMs are injected into the building envelopes, they improved the sensible/latent storage features of the envelopes. In this study, using numerical methods, defining first (no PCM), second (PCM without phase transition), and third building (with phase transition), the importance of sensible storage feature was compared to latent one. It was found that the sensible/latent importance is dependent on the thermal resistance of the envelopes and setpoint. At setpoint 22 °C, it was found that the PCM-enhanced building consumed less power by 32.4 kWhm2. Under this condition, the share of sensible storage as well as latent storage was 54% and 46%, respectively. The reason for the lower share of latent storage was that PCM never participated in phase change about 40% of the year. To boost PCM effectiveness, it was found that the PCM installation near the uppermost layer enhanced energy-saving by 3.72 kWhm2. The presence of phase change in PCM is not always considered a positive point. In one situation, it was observed that if PCM did not undergo phase transition, it reduces energy consumption by 9.4 kWhm2, while for PCM with phase transition this value was 7.1 kWhm2. PCM was also beneficial on CO 2 reduction either with phase change or without phase change. In the former, CO 2 emissions declined by 34.9 kgm2, and under the latter circumstances it was 23.9 kgm2.