Numerical investigation of photothermal performance of glazed window integrated with airflow channel and phase change material

Double-glazed window coupled with phase change material (PCM) improves the thermal inertia and heat storage capacity, but the inefficient utilization of latent heat stored in PCM restricts the application in cold regions in winter. To surmount the deficiencies, a PCM ventilation window (PCMVW) with an airflow channel installed outside is proposed, in which the external ambient air enters the room after being heated by the PCM layer to realize the adequate utilization and recovery of the energy stored in the PCM. A two-dimensional model was established to investigate the photothermal performance of PCMVW in winter. Then, the effects of airflow rate and PCM melting point on the photothermal performance of PCMVW are analyzed. The results show that the thermal performance of the structure achieves significant enhancement with the airflow channel installed, which saves 521 kJ/d of energy, and the temperature fluctuation is 0.68 times that of the traditional PCMW. Meanwhile, the airflow improves the dynamic transmittance of the window at certain times. Remarkable enhancement of the thermal performance and optical performance of the PCMVW is achieved by adjusting the air mass flow rate and PCM melting point, which provides solutions for the application of PCMVW in cold regions.