Energy performance analysis of prototype electrochromic windows
This paper presents the results of a study investigating the energy performance of three newly developed prototype electrochromic devices. The DOE-2.1 E energy simulation program was used to analyze the annual cooling, lighting, and total electric energy use and peak demand as a function of window type and size. The authors simulated a prototypical commercial office building module located in the cooling-dominated locations of Phoenix, AZ and Miami, FL. Heating energy use was also studied in the heating-dominated location of Madison, WI. Daylight illuminance was used to control electrochromic state-switching. Two types of window systems were analyzed; i.e., the outer pane electrochromic glazing was combined with either a conventional low-E or a spectrally selective inner pane. The properties of the electrochromic glazings are based on measured data of new prototypes developed as part of a cooperative DOE-industry program. The results show the largest difference in annual electric energy performance between the different window types occurs in Phoenix and is about 6.5 kWh/m{sup 2} floor area (0.60 kWh/ft{sup 2}) which can represent a cost of about $$.52/m{sup 2} ($$.05/ft{sup 2}) using electricity costing $.08/kWh. In heating-dominated locations, the electrochromic should be maintained in its bleached state during the heating season to take advantage of beneficial solar heat gain which would reduce the amount of required heating. This also means that the electrochromic window with the largest solar heat gain coefficient is best.
- Research Organization:
- Lawrence Berkeley National Lab., CA (United States)
- Sponsoring Organization:
- USDOE Assistant Secretary for Energy Efficiency and Renewable Energy, Washington, DC (United States)
- DOE Contract Number:
- AC03-76SF00098
- OSTI ID:
- 495755
- Report Number(s):
- LBNL--39905; CONF-970668--3; ON: DE97006574
- Country of Publication:
- United States
- Language:
- English
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