skip to main content
DOE PAGES title logo U.S. Department of Energy
Office of Scientific and Technical Information

This content will become publicly available on October 1, 2020

Title: Roof ponds combined with a water-to-air heat exchanger as a passive cooling system: Experimental comparison of two system variants

Abstract

Two roof pond configurations combined with a water-to-air heat exchanger (WAHE) are evaluated. Test cells of 1.35 m × 1.35 m x 1.35 m with the same thermal properties, except for the roofs, are built in a hot-dry climate with mild winters. They are connected with a WAHE placed inside the roof pond's water by a pipe through which the indoor air is re-circulated. The first roof consists of a 0.35 m deep water pond covered with a floating polystyrene insulation 0.03 m thick, and a spray system located 0.5 m above it that operates at night. The second roof is covered with an aluminum plate separated by a 0.10 m air gap above a 0.25 m deep water pond. We ran multiple series and compared the results to a control cell that had a California energy code compliant insulated roof. Predictive equations are developed to dimension the WAHE system. Results demonstrate that the cells with roof ponds have better cooling performance than the code compliant control cell. The best performance is obtained in the cell with the WAHE operating continuously. In this case, the indoor temperature stayed below 24 °C even with ambient temperatures above 35 °C.

Authors:
ORCiD logo [1];  [2]
  1. Univ. of Seville (Spain). School of Architecture
  2. California Polytechnic Pomona Univ. (CalPoly), CA (United States). Dept. of Architecture
Publication Date:
Research Org.:
Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
Sponsoring Org.:
USDOE Office of Science (SC)
OSTI Identifier:
1559254
Grant/Contract Number:  
AC02-05CH11231
Resource Type:
Accepted Manuscript
Journal Name:
Renewable Energy
Additional Journal Information:
Journal Volume: 141; Journal Issue: C; Journal ID: ISSN 0960-1481
Publisher:
Elsevier
Country of Publication:
United States
Language:
English
Subject:
32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATION; roof pond; water-to-air heat exchanger; passive cooling; evaporative cooling; thermal energy storage; physical testing – mockups.

Citation Formats

Almodovar, José Manuel, and La Roche, Pablo. Roof ponds combined with a water-to-air heat exchanger as a passive cooling system: Experimental comparison of two system variants. United States: N. p., 2019. Web. doi:10.1016/j.renene.2019.03.148.
Almodovar, José Manuel, & La Roche, Pablo. Roof ponds combined with a water-to-air heat exchanger as a passive cooling system: Experimental comparison of two system variants. United States. doi:10.1016/j.renene.2019.03.148.
Almodovar, José Manuel, and La Roche, Pablo. Tue . "Roof ponds combined with a water-to-air heat exchanger as a passive cooling system: Experimental comparison of two system variants". United States. doi:10.1016/j.renene.2019.03.148.
@article{osti_1559254,
title = {Roof ponds combined with a water-to-air heat exchanger as a passive cooling system: Experimental comparison of two system variants},
author = {Almodovar, José Manuel and La Roche, Pablo},
abstractNote = {Two roof pond configurations combined with a water-to-air heat exchanger (WAHE) are evaluated. Test cells of 1.35 m × 1.35 m x 1.35 m with the same thermal properties, except for the roofs, are built in a hot-dry climate with mild winters. They are connected with a WAHE placed inside the roof pond's water by a pipe through which the indoor air is re-circulated. The first roof consists of a 0.35 m deep water pond covered with a floating polystyrene insulation 0.03 m thick, and a spray system located 0.5 m above it that operates at night. The second roof is covered with an aluminum plate separated by a 0.10 m air gap above a 0.25 m deep water pond. We ran multiple series and compared the results to a control cell that had a California energy code compliant insulated roof. Predictive equations are developed to dimension the WAHE system. Results demonstrate that the cells with roof ponds have better cooling performance than the code compliant control cell. The best performance is obtained in the cell with the WAHE operating continuously. In this case, the indoor temperature stayed below 24 °C even with ambient temperatures above 35 °C.},
doi = {10.1016/j.renene.2019.03.148},
journal = {Renewable Energy},
number = C,
volume = 141,
place = {United States},
year = {2019},
month = {10}
}

Journal Article:
Free Publicly Available Full Text
This content will become publicly available on October 1, 2020
Publisher's Version of Record

Save / Share: