Assessment of Electrochromic Glazing Impact on Occupants Thermal Comfort and Building Energy Performance

Access to natural daylight and connection to the outdoor environment is one of the key elements of contemporary architecture. This design concept ischaracterized in buildings by large area glazing. However, large openings without proper shading strategy can cause visual and thermal discomfort foroccupants in building perimeter zones. Electrochromic glazing can dynamically tint and vary its visual and thermal properties. EC glazing can preventlarge amounts of solar energy from passing into the building interior to prevent over-heating.This study focuses on analyzing how Electrochromic (EC) glazing can affect: 1) Whole building energy performance and 2) Occupant thermal comfort.Building energy performance was modeled using parametric modeling tool based on Energy plus simulation engine. Advanced human thermal comfortmodel developed by UC Berkeley and Center for Built Environment (CBE) was used in this study to predict body comfort and sensation. The level ofaccuracy of advanced thermal comfort model which can predict comfort for local body parts makes it a unique tool for assessment of comfort under nonuniformenvironments, which is common due to variation in solar angle and solar radiation intensity that transmitted through Electrochromic glazing inthe multi-zone configuration.A higher education building was selected as a case study for a whole building energy analysis comparing energy performance of the EC glazing versus low-E window. For analyzing thermal comfort performance of the Electrochromic glazing, two identical offices spaces one with Electrochromic glazing inmulti-zone configuration and one with low-E glazing were modeled. Thermal comfort and sensation of a manikin were compared from both rooms at localand overall level. The analysis result showed that multi-zone Electrochromic glazing could significantly improve the thermal comfort levels of manikinmodel. Analysis result was reported in terms of color-coded manikin and interior solar radiation model for the selected hours that occupant receives directsunlight penetration.