The Energy Performance of Electrochromic Windows in Heating-Dominated Geographic Locations

TitleThe Energy Performance of Electrochromic Windows in Heating-Dominated Geographic Locations
Publication TypeConference Paper
Year of Publication1996
AuthorsRobert Sullivan, Eleanor S Lee, Michael D Rubin, Stephen E Selkowitz
Conference NameSPIE International Symposium on Optical Materials Technology for Energy Efficiency & Solar Energy Conversion XV
Date Published09/1996
Conference LocationFreiburg, Germany
Call NumberLBL-38252

This paper presents the results of a study investigating the energy performance of electrochromic windows in heating-dominated geographic locations under a variety of state-switching control strategies. We used the DOE-2.1E energy simulation program to analyze the annual heating, cooling and lighting energy use and performance as a function of glazing type, size, and electrochromic control strategy. We simulated a prototypical commercial office building module located in Madison, Wisconsin. Control strategies analyzed were based on daylight illuminance, incident total solar radiation, and space cooling load. Our results show that overall energy performance is best if the electrochromic is left in its clear or bleached state during the heating season, but controlled during the cooling season using daylight illuminance as a control strategy. Even in such heating dominated locations as Madison, there is still a well-defined cooling season when electrochromic switching will be beneficial. However, having the electrochromic remain in its bleached state during the winter season may result in glare and visual comfort problems for occupants much in the same way as conventional glazings.

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