Determination of Heat Gain through Different Types of Building-Integrated Photovoltaic Façade Combined with Phase Change Material and Smart Glazing

This study aims to design and evaluate the thermal performance of an intelligent building glazing system that integrates building-integrated photovoltaic (BIPV), phase change material (PCM), and smart glazing (SG) technologies to enhance building energy efficiency. The system comprises semi-transparent solar cells for electricity generation, a PCM layer for absorbing and releasing latent heat, and SG for dynamic optical control. The research employed theoretical calculations under steady-state conditions to compare six window configurations under typical tropical conditions. The results showed that the BIPV-PCM-SG system in off mode achieved the lowest overall heat transfer coefficient (U-value) of 2.67 W/m2K and reduced heat gain to only 389.73 W, representing a 56% reduction in transmitted heat compared to a conventional clear glazing window. These results highlight the synergistic effect of combining solar energy conversion, latent heat buffering, and optical modulation. The findings establish a fundamental design basis for low-energy buildings and promote the Net- Zero-Energy Building concept, which aligns with Thailand's sustainable energy policies. This research provides a foundational guideline for designing future energy-efficient façades in tropical climates.