Thermal and visual comfort analysis of adaptive vacuum integrated switchable suspended particle device window for temperate climate

Abstract

In this work, thermal and visual comfort of low heat loss switchable suspended particle device-vacuum (SPD-vacuum) glazing was investigated for less energy-hungry adaptive building’s glazing or façade integration at temperate climate. This SPD-vacuum glazing had 38% visible transmittance in the presence of 110 V applied an alternating voltage and 2% visible transmittance in the absence of electrical power. Outdoor test cell characterisation was employed to measure the thermal and daylighting parameters of this glazing. Solar heat gain or solar factor was calculated using non calorimetric methods and varied between 0.38 (Switch OFF/opaque) to 0.51 (Switch ON/ transparent). Test cell indoor and ambient parameters (incident solar radiation and ambient temperature) were engaged for thermal comfort analysis by using PMV and PPD methods. Visual comfort was analysed from glare potential, useful daylight index, and colour properties. The comfortable thermal environment was attainable using both states of this glazing for a clear sunny day. Acceptable daylight throughout the day was possible for a clear sunny day for opaque state; however clear state offered allowable/comfortable correlated colour temperature (CCT) of 5786.18 K and colour rendering index (CRI) of 94.83.