Study of phase change material on alleviating building overheating risk in cold regions of China

Rising summer overheating risk in China's cold regions due to climate change has drawn significant attention. Phase change material (PCM) has lowered indoor temperatures and saved energy in some areas, but its suitability and optimal phase change temperature in cold climates remain unconfirmed. This study evaluated overheating risks and assessed PCM's potential impact within these regions. The indoor temperature of an office building was monitored from May to September 2022 to track overheating instances. This measurement data was also used to simulate the PCM's effect in EnergyPlus. According to CIBSE TM52, Yichun experienced 255 h (13.89% of total time) of overheating, Harbin had 744 h (40.54%), Shenyang had 1173 h (63.89%), and Dalian had 1255 h (68.36%). Using PCM could reduce overheating hours by 198 h (10.78%) in Yichun, 346 h (18.85%) in Harbin, 351 h (19.12%) in Shenyang, and 204 h (11.11%) in Dalian. Additionally, it potentially reduced energy consumption by 4.56%-30.57% across these cities. To address climate change challenges, policymakers are suggested to contemplate implementing PCM as an effective measure to protect existing buildings from summer heat in the cold regions of China.