This study evaluated the building cooling capacity of sky radiation, which was previously identified to have the greatest cooling potential among common ambient sources for climates across the U.S. A heat pipe augmented sky radiator system was simulated by a thermal network with nine nodes, including a thin polyethylene cover with and without condensation, white (zinc oxide) painted radiator plate, condenser and evaporator ends of the heat pipe, thermal storage fluid (water), tank wall, room, sky and ambient air. Heat transfer between nodes included solar flux and sky radiation to cover and plate, wind convection and radiation from cover to ambient, radiation from plate to ambient, natural convection and radiation from plate to cover, conduction from plate to condenser, two-phase heat transfer from evaporator to condenser, natural convection from evaporator to water and from water to tank wall, natural convection and radiation from tank wall to room, and overall heat loss from room to ambient. A thin layer of water was applied to simulate condensation on the cover. Nodal temperatures were simultaneously solved as functions of time using typical meteorological year (TMY3) weather data. Auxiliary cooling was added as needed to limit room temperature to a maximum of 23.9 °C. For this initial investigation, a moderate climate (Louisville, KY) was used to evaluate the effects of radiator orientation, thermal storage capacity, and cooling load to radiator area ratio (LRR). Results were compared to a Louisville baseline with LRR = 10 W/m2 K, horizontal radiator and one cover, which provided an annual sky fraction (fraction of cooling load provided by sky radiation) of 0.855. A decrease to 0.852 was found for an increase in radiator slope to 20 deg, and a drop to 0.832 for 53 deg slope (latitude + 15 deg, a typical slope for solar heating). These drops were associated with increases in average radiator temperature by 0.73 °C for 20 deg and 1.99 °C for 53 deg. A 30% decrease in storage capacity caused a decrease in sky fraction to 0.843. Sky fractions were 0.720 and 0.959 for LRR of 20 and 5, respectively. LRR and thermal storage capacity had strong effects on performance. Radiator slope had a surprisingly small impact, considering that the view factor to the sky at 53 deg tilt is less than 0.5.
Skip Nav Destination
Article navigation
August 2019
Research-Article
The Cooling Potential of Sky Radiation With Variations in System Parameters
M. Adrienne Parsons,
M. Adrienne Parsons
Department of Mechanical Engineering,
University of Louisville,
Louisville, KY 40299
e-mail: amsond01@louisville.edu
University of Louisville,
Louisville, KY 40299
e-mail: amsond01@louisville.edu
Search for other works by this author on:
M. Keith Sharp
M. Keith Sharp
Department of Mechanical Engineering,
University of Louisville,
Louisville, KY 40299
e-mail: keith.sharp@louisville.edu
University of Louisville,
Louisville, KY 40299
e-mail: keith.sharp@louisville.edu
Search for other works by this author on:
M. Adrienne Parsons
Department of Mechanical Engineering,
University of Louisville,
Louisville, KY 40299
e-mail: amsond01@louisville.edu
University of Louisville,
Louisville, KY 40299
e-mail: amsond01@louisville.edu
M. Keith Sharp
Department of Mechanical Engineering,
University of Louisville,
Louisville, KY 40299
e-mail: keith.sharp@louisville.edu
University of Louisville,
Louisville, KY 40299
e-mail: keith.sharp@louisville.edu
Contributed by the Solar Energy Division of ASME for publication in the JOURNAL OF SOLAR ENERGY ENGINEERING: INCLUDING WIND ENERGY AND BUILDING ENERGY CONSERVATION. Manuscript received September 26, 2017; final manuscript received December 20, 2018; published online February 19, 2019. Assoc. Editor: Ming Qu.
J. Sol. Energy Eng. Aug 2019, 141(4): 041007 (9 pages)
Published Online: February 19, 2019
Article history
Received:
September 26, 2017
Revised:
December 20, 2018
Citation
Parsons, M. A., and Sharp, M. K. (February 19, 2019). "The Cooling Potential of Sky Radiation With Variations in System Parameters." ASME. J. Sol. Energy Eng. August 2019; 141(4): 041007. https://doi.org/10.1115/1.4042453
Download citation file:
159
Views
0
Citations
Get Email Alerts
Cited By
Material Selection and Corrosion Studies of Candidate Bearing Materials for Use in Molten Chloride Salt
J. Sol. Energy Eng (April 2023)
Thermal Model of a Parabolic Trough Solar Field With a Closed-Loop Operation During Sunrise Period
J. Sol. Energy Eng (February 2023)
Related Articles
Effect of Environmental Phase Characteristics on the Discharge of a Thermal Storage System
J. Sol. Energy Eng (August,2001)
Heat Transfer Characteristics of Oscillating Heat Pipe With Water and Ethanol as Working Fluids
J. Heat Transfer (December,2010)
Thermal and Visual Observation of Water and Acetone Oscillating Heat Pipes
J. Heat Transfer (June,2011)
Comparative Study on Thermal Performance of Ultrathin Miniature Loop Heat Pipes With Different Internal Wicks
J. Heat Transfer (December,2017)
Related Chapters
The Special Characteristics of Closed-Cycle Gas Turbines
Closed-Cycle Gas Turbines: Operating Experience and Future Potential
Thermal Design Guide of Liquid Cooled Systems
Thermal Design of Liquid Cooled Microelectronic Equipment
Radiation
Thermal Management of Microelectronic Equipment