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Title: Cool roofs save energy

Abstract

Dark roofs are heated by the summer sun and, thus, raise the summertime cooling demand of buildings. For highly absorptive roofs, the difference between the surface and ambient air temperatures may be as high as 50 C (90 F), while for highly reflective roofs with similar insulative properties, the difference is only about 10 C. For this reason, cool roofs are effective in reducing cooling energy use. Typically, cool roofs incur no additional cost if changes are incorporated into routine reroofing schedules. Several experiments on individual buildings in California and Florida show that painting roofs white reduces the air-conditioning load between 10% and 50% (corresponding to savings ranging from $10 to $100 per year per 100 m{sup 2}), depending on the thickness of insulation under the roof. The savings, of course, are strong functions of the thermal integrity of a building and climatic conditions. This paper focuses on field data documenting the impact of cool roofs in reducing cooling energy use in several residential and commercial buildings in northern California and in Florida. Simulated savings for several US metropolitan areas are also presented. Finally, policy and implementation issues such as ratings and ASHRAE standards are briefly discussed.

Authors:
 [1]
  1. Lawrence Berkeley National Lab., CA (United States)
Publication Date:
Sponsoring Org.:
USDOE Assistant Secretary for Energy Efficiency and Renewable Energy, Washington, DC (United States)
OSTI Identifier:
649412
Report Number(s):
CONF-980123-
Journal ID: ISSN 0001-2505; TRN: IM9825%%25
DOE Contract Number:  
AC03-76SF00098
Resource Type:
Conference
Resource Relation:
Conference: 1998 ASHRAE winter meeting, San Francisco, CA (United States), 17-21 Jan 1998; Other Information: PBD: 1998; Related Information: Is Part Of ASHRAE transactions 1998. Volume 104, Part 1B: Symposium papers; PB: 1162 p.
Country of Publication:
United States
Language:
English
Subject:
32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATION; ROOFS; REFLECTIVE COATINGS; ENERGY CONSUMPTION; COOLING LOAD; RESIDENTIAL BUILDINGS; COMMERCIAL BUILDINGS; CALIFORNIA; FLORIDA; URBAN AREAS

Citation Formats

Akbari, H. Cool roofs save energy. United States: N. p., 1998. Web.
Akbari, H. Cool roofs save energy. United States.
Akbari, H. Thu . "Cool roofs save energy". United States.
@article{osti_649412,
title = {Cool roofs save energy},
author = {Akbari, H.},
abstractNote = {Dark roofs are heated by the summer sun and, thus, raise the summertime cooling demand of buildings. For highly absorptive roofs, the difference between the surface and ambient air temperatures may be as high as 50 C (90 F), while for highly reflective roofs with similar insulative properties, the difference is only about 10 C. For this reason, cool roofs are effective in reducing cooling energy use. Typically, cool roofs incur no additional cost if changes are incorporated into routine reroofing schedules. Several experiments on individual buildings in California and Florida show that painting roofs white reduces the air-conditioning load between 10% and 50% (corresponding to savings ranging from $10 to $100 per year per 100 m{sup 2}), depending on the thickness of insulation under the roof. The savings, of course, are strong functions of the thermal integrity of a building and climatic conditions. This paper focuses on field data documenting the impact of cool roofs in reducing cooling energy use in several residential and commercial buildings in northern California and in Florida. Simulated savings for several US metropolitan areas are also presented. Finally, policy and implementation issues such as ratings and ASHRAE standards are briefly discussed.},
doi = {},
journal = {},
issn = {0001-2505},
number = ,
volume = ,
place = {United States},
year = {1998},
month = {10}
}

Conference:
Other availability
Please see Document Availability for additional information on obtaining the full-text document. Library patrons may search WorldCat to identify libraries that hold this conference proceeding.

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