Evaluation of optical properties and protection factors of a PDLC switchable glazing for low energy building integration

Polymer dispersed liquid crystal (PDLC) glazing is a potential electrically actuated switchable adaptive glazing for low energy building application as it become transparent in the presence of alternating current (AC) power supply and become translucent/opaque without power supply. Optical properties and protection factor for a particular type of PDLC glazing was investigated in this work. Using UV-vis-NIR (1050) spectrophotometer spectral transmittance of this glazing was measured for its both states. PDLC on state needs 20 V AC power supply to offer 41% transmission while without any supply this glazing becomes 23% transparent. In the switch off state LC particles offer forward scattering which makes this glazing translucent with high 82.6% haze. Solar factor for PDLC transparent and translucent state was found to be 0.53 and 0.39 respectively. Glazing protection factors were calculated using spectral transmittance data. Switchable transparency and switchable solar factor makes this glazing suitable to match adaptability of building occupants.