Behaviour of a SPD switchable glazing in an outdoor test cell with heat removal under varying weather conditions

Suspended particle device (SPD) switchable glazing has potential to control transmission of solar radiation in the visible range by changing its transparency from 55% to 5%. Outdoor test cell characterisation of a SPD switchable glazing offered the dynamic solar heat gain coefficient (SHGC) which varied between 0.05 (when opaque) and 0.38 (when transparent). Reduction of maximum temperature rise of 11% and 15% was possible using SPD “transparent” and “opaque” state compared to same area double-glazing. Insulated test cell with water flow heat exchanger was employed to measure the cooling load reduction potential of SPD glazing while its transmission changed from “transparent” to “opaque” state. A cooling load reduction up to 6 kW h for a 0.343 m³ volume test cell was possible by changing a 0.21 m × 0.28 m SPD glazing transparency from “transparent” to “opaque”. Average overall heat transfer coefficient of SPD glazing varied between 5.02 W/m² K and 5.2 W/m² K for two different states.