Achieving daytime thermal comfort with radiant sky-cooling
department or school: Applied Science, Faculty of
department or school: Mechanical Engineering, Department of
data provider: DSpace
degree campus: UBCV
creator: Gerrard, Kyle
issued: 2025-05-02T13:18:15Z
issued: 2025
related degree: Master of Applied Science - MASc
degree grantor: University of British Columbia
description: Radiant sky cooling offers a sustainable solution for improving thermal comfort in semitransient public spaces, such as outdoor seating areas, open-air corridors, and transit stations. By optimizing the material spectral emissivity, it is possible to limit solar heat gains and emit strongly through the atmosphere to deep space to achieve a net-negative heat balance and cool a surface below ambient temperatures even in direct sunlight. This work explores the potential of radiant sky cooling to mitigate heat stress without using electricity or actively conditioning a controlled air volume. Through a 2-month field test of a full-size 4’x4’ custom radiant cooling panel this study was able to examine the efficacy of the Radi-Cool commercial radiant film product and calibrate thermal models for use in design planning. A Phase Change Material (PCM) was also synthesized and tested, then added to the underside of the cooling panel to explore the performance benefits of such a material in maintaining adequately low daytime temperatures. The performance of the cooling panel was also compared against a typical urban tree canopy to assess whether a cooling structure based on a similar panel could be a viable alternative to vegetation for decreasing the mean radiant temperature (MRT) experienced by an occupant. Results indicate that a PCM is an excellent candidate to enhance radiant sky-cooling due to its high thermal mass to weight ratio and ability to extend time in desired temperature ranges. The calibrated thermal model also allows the potential for designers to test better performing materials, different orientations and tilts, and assesses real-world factors such as surface fouling and convective losses. This work demonstrates that radiant sky cooling is a viable, low-energy intervention for enhancing the thermal experience in semi-outdoor environments, contributing to sustainable urban cooling strategies.
aggregated CHO: https://circle.library.ubc.ca/rest/handle/2429/90956
note: Achieving Daytime Thermal Comfortwith Radiant Sky-CoolingbyKyle GerrardB.ASc., The University of British Columbia, 2022A THESIS SUBMITTED IN PARTIAL FULFILLMENT OFTHE REQUIREMENTS FOR THE DEGREE OFMASTER OF APPLIED SCIENCEinThe Faculty of Graduate and Postdoctoral Studies(Mechanical Engineering)THE UNIVERSITY OF BRITISH COLUMBIA(Vancouver)April 2025© Kyle Gerrard 2025The following individuals certify that they have read, and recommend tothe Faculty of Graduate and Postdoctoral Studies for acceptance, the thesisentitled:Achieving Daytime Thermal Comfort with Radiant Sky-Coolingsubmitted by Kyle Gerrard in partial fulfillment of the requirements forthe degree of Master of Applied Science in Mechanical Engineering.Examining Committee:Adam Rysanek, Associate Professor, School of Architecture and LandscapeArchitecture, UBCSupervisorSteven Rogak, Professor, Mechanical Engineering, UBCCo-supervisorPatrick Kirchen, Associate Professor, Mechanical Engineering, UBCSupervisory Committee MemberForrest Meggars, Associate Professor, Andlinger Center for Energy and theEnvironment, Princeton UniversityAdditional ExamineriiAbstractRadiant sky cooling offers a sustainable solution for improving thermal com-fort in semitransient public spaces, such as outdoor seating areas, open-aircorridors, and transit stations. By optimizing the material spectral emis-sivity, it is possible to limit solar heat gains and emit strongly through theatmosphere to deep space to achieve a net-negative heat balance and coola surface below ambient temperatures even in direct sunlight. This workexplores the potential of radiant sky cooling to mitigate heat stress withoutusing electricity or actively conditioning a controlled air volume. Througha 2-month field test of a full-size 4’x4’ custom radiant cooling panel thisstudy was able to examine the efficacy of the Radi-Cool commercial radiantfilm product and calibrate thermal models for use in design planning. APhase Change Material (PCM) was also synthesized …
has type: Thesis/Dissertation
date issued: 2025-05
is shown at: 10.14288/1.0448708
language: eng
degree discipline: Mechanical Engineering
provider: Vancouver : University of British Columbia Library
publisher: University of British Columbia
rights: Attribution-NonCommercial-NoDerivatives 4.0 International
rights URI: http://creativecommons.org/licenses/by-nc-nd/4.0/
scholar level: Graduate
contributor: Rysanek, Adam
contributor: Rogak, Steve
type: Text
identifier URI: http://hdl.handle.net/2429/90956