Numerical and Experimental Analysis of Thermal Performance in Triple-Glazed Low-E Windows for Iraqi Weather

Low-emissivity (low-e) glass is a highly efficient material capable of adapting its thermal and optical properties in response to temperature fluctuations without consuming additional Energy. This makes it an ideal choice for passive building envelopes, particularly in climates with extreme temperatures. In this study, the thermal efficiency of triple-glazed windows incorporating low-e glass was experimentally evaluated under the harsh summer conditions of Iraq. Specifically, a conventional triple-glazed window (TG1) with air-filled gaps was compared to a modified version (TG2) featuring low-e glass on the outer pane, also with air in both gaps. The research findings revealed that when solar radiation peaked at 650 W/m² around midday in July, the internal surface temperatures of TG1 and TG2 were 36.4°C and 32.4°C, respectively. The temperature reduction observed in TG2, amounting to 4°C (10.9%), highlights the significant thermal advantage the low-e glass provides, making it a superior option for enhancing energy efficiency in buildings.