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Title: Soiling of building envelope surfaces and its effect on solar reflectance – Part II: Development of an accelerated aging method for roofing materials

Abstract

Highly reflective roofs can decrease the energy required for building air conditioning, help mitigate the urban heat island effect, and slow global warming. However, these benefits are diminished by soiling and weathering processes that reduce the solar reflectance of most roofing materials. Soiling results from the deposition of atmospheric particulate matter and the growth of microorganisms, each of which absorb sunlight. Weathering of materials occurs with exposure to water, sunlight, and high temperatures. This study developed an accelerated aging method that incorporates features of soiling and weathering. The method sprays a calibrated aqueous soiling mixture of dust minerals, black carbon, humic acid, and salts onto preconditioned coupons of roofing materials, then subjects the soiled coupons to cycles of ultraviolet radiation, heat and water in a commercial weatherometer. Three soiling mixtures were optimized to reproduce the site-specific solar spectral reflectance features of roofing products exposed for 3 years in a hot and humid climate (Miami, Florida); a hot and dry climate (Phoenix, Arizona); and a polluted atmosphere in a temperate climate (Cleveland, Ohio). A fourth mixture was designed to reproduce the three-site average values of solar reflectance and thermal emittance attained after 3 years of natural exposure, which the Cool Roofmore » Rating Council (CRRC) uses to rate roofing products sold in the US. This accelerated aging method was applied to 25 products₋single ply membranes, factory and field applied coatings, tiles, modified bitumen cap sheets, and asphalt shingles₋and reproduced in 3 days the CRRC's 3-year aged values of solar reflectance. In conclusion, this accelerated aging method can be used to speed the evaluation and rating of new cool roofing materials.« less

Authors:
 [1];  [2];  [1];  [1]; ORCiD logo [1];  [1];  [2];  [1];  [1];  [1];  [3];  [1];  [1]
  1. Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
  2. Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Univ. of California, Berkeley, CA (United States)
  3. Concordia Univ., Montreal (Canada)
Publication Date:
Research Org.:
Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
Sponsoring Org.:
Environmental Energy Technologies Division
OSTI Identifier:
1163272
Report Number(s):
LBNL-6714E
Journal ID: ISSN 0927-0248
DOE Contract Number:  
AC02-05CH11231
Resource Type:
Journal Article
Journal Name:
Solar Energy Materials and Solar Cells
Additional Journal Information:
Journal Volume: 122; Journal Issue: C; Related Information: Journal Publication Date: 03/2014; Journal ID: ISSN 0927-0248
Publisher:
Elsevier
Country of Publication:
United States
Language:
English
Subject:
54 ENVIRONMENTAL SCIENCES; Cool roofs; Soiling; Weathering; Natural exposure; Accelerated aging; Soot

Citation Formats

Sleiman, Mohamad, Kirchstetter, Thomas W., Berdahl, Paul, Gilbert, Haley E., Quelen, Sarah, Marlot, Lea, Preble, Chelsea V., Chen, Sharon, Montalbano, Amandine, Rosseler, Olivier, Akbari, Hashem, Levinson, Ronnen, and Destaillats, Hugo. Soiling of building envelope surfaces and its effect on solar reflectance – Part II: Development of an accelerated aging method for roofing materials. United States: N. p., 2014. Web. doi:10.1016/j.solmat.2013.11.028.
Sleiman, Mohamad, Kirchstetter, Thomas W., Berdahl, Paul, Gilbert, Haley E., Quelen, Sarah, Marlot, Lea, Preble, Chelsea V., Chen, Sharon, Montalbano, Amandine, Rosseler, Olivier, Akbari, Hashem, Levinson, Ronnen, & Destaillats, Hugo. Soiling of building envelope surfaces and its effect on solar reflectance – Part II: Development of an accelerated aging method for roofing materials. United States. https://doi.org/10.1016/j.solmat.2013.11.028
Sleiman, Mohamad, Kirchstetter, Thomas W., Berdahl, Paul, Gilbert, Haley E., Quelen, Sarah, Marlot, Lea, Preble, Chelsea V., Chen, Sharon, Montalbano, Amandine, Rosseler, Olivier, Akbari, Hashem, Levinson, Ronnen, and Destaillats, Hugo. 2014. "Soiling of building envelope surfaces and its effect on solar reflectance – Part II: Development of an accelerated aging method for roofing materials". United States. https://doi.org/10.1016/j.solmat.2013.11.028. https://www.osti.gov/servlets/purl/1163272.
@article{osti_1163272,
title = {Soiling of building envelope surfaces and its effect on solar reflectance – Part II: Development of an accelerated aging method for roofing materials},
author = {Sleiman, Mohamad and Kirchstetter, Thomas W. and Berdahl, Paul and Gilbert, Haley E. and Quelen, Sarah and Marlot, Lea and Preble, Chelsea V. and Chen, Sharon and Montalbano, Amandine and Rosseler, Olivier and Akbari, Hashem and Levinson, Ronnen and Destaillats, Hugo},
abstractNote = {Highly reflective roofs can decrease the energy required for building air conditioning, help mitigate the urban heat island effect, and slow global warming. However, these benefits are diminished by soiling and weathering processes that reduce the solar reflectance of most roofing materials. Soiling results from the deposition of atmospheric particulate matter and the growth of microorganisms, each of which absorb sunlight. Weathering of materials occurs with exposure to water, sunlight, and high temperatures. This study developed an accelerated aging method that incorporates features of soiling and weathering. The method sprays a calibrated aqueous soiling mixture of dust minerals, black carbon, humic acid, and salts onto preconditioned coupons of roofing materials, then subjects the soiled coupons to cycles of ultraviolet radiation, heat and water in a commercial weatherometer. Three soiling mixtures were optimized to reproduce the site-specific solar spectral reflectance features of roofing products exposed for 3 years in a hot and humid climate (Miami, Florida); a hot and dry climate (Phoenix, Arizona); and a polluted atmosphere in a temperate climate (Cleveland, Ohio). A fourth mixture was designed to reproduce the three-site average values of solar reflectance and thermal emittance attained after 3 years of natural exposure, which the Cool Roof Rating Council (CRRC) uses to rate roofing products sold in the US. This accelerated aging method was applied to 25 products₋single ply membranes, factory and field applied coatings, tiles, modified bitumen cap sheets, and asphalt shingles₋and reproduced in 3 days the CRRC's 3-year aged values of solar reflectance. In conclusion, this accelerated aging method can be used to speed the evaluation and rating of new cool roofing materials.},
doi = {10.1016/j.solmat.2013.11.028},
url = {https://www.osti.gov/biblio/1163272}, journal = {Solar Energy Materials and Solar Cells},
issn = {0927-0248},
number = C,
volume = 122,
place = {United States},
year = {Thu Jan 09 00:00:00 EST 2014},
month = {Thu Jan 09 00:00:00 EST 2014}
}