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Title: Application issues for large-area electrochromic windows incommercial buildings

Abstract

Projections of performance from small-area devices to large-area windows and enterprise marketing have created high expectations for electrochromic glazings. As a result, this paper seeks to precipitate an objective dialog between material scientists and building-application scientists to determine whether actual large-area electrochromic devices will result in significant performance benefits and what material improvements are needed, if any, to make electrochromics more practical for commercial building applications. Few in-situ tests have been conducted with large-area electrochromic windows applied in buildings. This study presents monitored results from a full-scale field test of large-area electrochromic windows to illustrate how this technology will perform in commercial buildings. The visible transmittance (Tv) of the installed electrochromic ranged from 0.11 to 0.38. The data are limited to the winter period for a south-east-facing window. The effect of actual device performance on lighting energy use, direct sun control, discomfort glare, and interior illumination is discussed. No mechanical system loads were monitored. These data demonstrate the use of electrochromics in a moderate climate and focus on the most restrictive visual task: computer use in offices. Through this small demonstration, we were able to determine that electrochromic windows can indeed provide unmitigated transparent views and a level of dynamicmore » illumination control never before seen in architectural glazing materials. Daily lighting energy use was 6-24 percent less compared to the 11 percent-glazing, with improved interior brightness levels. Daily lighting energy use was 3 percent less to 13 percent more compared to the 38 percent-glazing, with improved window brightness control. The electrochromic window may not be able to fulfill both energy-efficiency and visual comfort objectives when low winter direct sun is present, particularly for computer tasks using cathode-ray tube (CRT) displays. However, window and architectural design as well as electrochromic control options are suggested as methods to broaden the applicability of electrochromics for commercial buildings. Without further modification, its applicability is expected to be limited during cold winter periods due to its slow switching speed.« less

Authors:
;
Publication Date:
Research Org.:
Ernest Orlando Lawrence Berkeley NationalLaboratory, Berkeley, CA (US)
Sponsoring Org.:
USDOE Assistant Secretary for Energy Efficiency andRenewable Energy. Office of Building Technology, State and CommunityPrograms. Office of Building Research and Standards
OSTI Identifier:
861174
Report Number(s):
LBNL-45841
Journal ID: ISSN 0927-0248; SEMCEQ; R&D Project: 474728; TRN: US200601%%692
DOE Contract Number:  
DE-AC02-05CH11231
Resource Type:
Journal Article
Journal Name:
Solar Energy Materials and Solar Cells
Additional Journal Information:
Journal Volume: 71; Journal Issue: 4; Related Information: Journal Publication Date: 03/01/2002; Journal ID: ISSN 0927-0248
Country of Publication:
United States
Language:
English
Subject:
32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATION; BRIGHTNESS; CATHODE RAY TUBES; COMMERCIAL BUILDINGS; COMPUTERS; ENERGY EFFICIENCY; FIELD TESTS; GLAZING MATERIALS; ILLUMINANCE; MARKETING; PERFORMANCE; SUN; VELOCITY; WINDOWS; electrochromic windows building applicationenergy-efficiency

Citation Formats

Lee, Eleanor S., and DiBartolomeo, D.L. Application issues for large-area electrochromic windows incommercial buildings. United States: N. p., 2000. Web.
Lee, Eleanor S., & DiBartolomeo, D.L. Application issues for large-area electrochromic windows incommercial buildings. United States.
Lee, Eleanor S., and DiBartolomeo, D.L. Mon . "Application issues for large-area electrochromic windows incommercial buildings". United States. https://www.osti.gov/servlets/purl/861174.
@article{osti_861174,
title = {Application issues for large-area electrochromic windows incommercial buildings},
author = {Lee, Eleanor S. and DiBartolomeo, D.L.},
abstractNote = {Projections of performance from small-area devices to large-area windows and enterprise marketing have created high expectations for electrochromic glazings. As a result, this paper seeks to precipitate an objective dialog between material scientists and building-application scientists to determine whether actual large-area electrochromic devices will result in significant performance benefits and what material improvements are needed, if any, to make electrochromics more practical for commercial building applications. Few in-situ tests have been conducted with large-area electrochromic windows applied in buildings. This study presents monitored results from a full-scale field test of large-area electrochromic windows to illustrate how this technology will perform in commercial buildings. The visible transmittance (Tv) of the installed electrochromic ranged from 0.11 to 0.38. The data are limited to the winter period for a south-east-facing window. The effect of actual device performance on lighting energy use, direct sun control, discomfort glare, and interior illumination is discussed. No mechanical system loads were monitored. These data demonstrate the use of electrochromics in a moderate climate and focus on the most restrictive visual task: computer use in offices. Through this small demonstration, we were able to determine that electrochromic windows can indeed provide unmitigated transparent views and a level of dynamic illumination control never before seen in architectural glazing materials. Daily lighting energy use was 6-24 percent less compared to the 11 percent-glazing, with improved interior brightness levels. Daily lighting energy use was 3 percent less to 13 percent more compared to the 38 percent-glazing, with improved window brightness control. The electrochromic window may not be able to fulfill both energy-efficiency and visual comfort objectives when low winter direct sun is present, particularly for computer tasks using cathode-ray tube (CRT) displays. However, window and architectural design as well as electrochromic control options are suggested as methods to broaden the applicability of electrochromics for commercial buildings. Without further modification, its applicability is expected to be limited during cold winter periods due to its slow switching speed.},
doi = {},
journal = {Solar Energy Materials and Solar Cells},
issn = {0927-0248},
number = 4,
volume = 71,
place = {United States},
year = {2000},
month = {5}
}