Experimental investigation on indoor thermal environment improvement and energy-saving of electrochromic window under Singapore's tropical climate

This study aims at analyzing the thermal performance improvement of a gray tintable electrochromic window (EC window) under Singapore's tropical climate. Two climate chambers were experimentally studied, one with a double-glazed EC window and another with a single-glazing window, the most common in the considered region, as the reference. The indoor thermal environment and air conditioning energy consumption were compared respectively to investigate the thermal performance improvement of the EC window. The results, under the sunny outdoor weather condition, showed that the EC window could achieve an interior surface temperature reduction of 4.4 degrees C under the tinted state and 3.0 degrees C under the clear state, compared to the reference window. Moreover, the bleached EC window achieved up to 37% improvement in peak Predicted Mean Vote (PMV) over the reference window, while the fully tinted EC window achieved a 50% improvement in peak PMV. Finally, the EC window under the fully tinted state could achieve up to 19% energy savings compared to the reference window. Using the EC window under Singapore's tropical climate can improve the occupant thermal comfort during the daytime and reduce air conditioning energy consumption.