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Modelling and testing a passive night-sky radiation system

dc.contributor.authorJoubert, G. D.en_ZA
dc.contributor.authorDobson, R. T.en_ZA
dc.date.accessioned2018-10-19T12:20:47Z
dc.date.available2018-10-19T12:20:47Z
dc.date.issued2017
dc.identifier.citationJoubert, G. D. & Dobson, R. T. 2017. Modelling and testing a passive night-sky radiation system. Journal of Energy in Southern Africa, 28(1):76-90, doi:10.17159/2413-3051/2017/v28i1a1550
dc.identifier.issn2413-3051 (online)
dc.identifier.issn1021-447X (print)
dc.identifier.otherdoi:10.17159/2413-3051/2017/v28i1a1550
dc.identifier.urihttp://hdl.handle.net/10019.1/104579
dc.descriptionCITATION: Joubert, G. D. & Dobson, R. T. 2017. Modelling and testing a passive night-sky radiation system. Journal of Energy in Southern Africa, 28(1):76-90, doi:10.17159/2413-3051/2017/v28i1a1550.
dc.descriptionThe original publication is available at https://journals.assaf.org.za/jesa
dc.description.abstractENGLISH ABSTRACT: The as-built and tested passive night-sky radiation cooling/heating system considered in this investigation consists of a radiation panel, a cold water storage tank, a hot water storage tank, a room and the interconnecting pipework. The stored cold water can be used to cool a room during the day, particularly in summer. A theoretical time-dependent thermal performance model was also developed and compared with the experimental results and it is shown that the theoretical simulation model captures the experimental system performance to within a reasonable degree of accuracy. A natural circulation experimental set-up was constructed and subsequently used to show that under local (Stellenbosch, South Africa) conditions the typical heat-removal rate from the water in the tank is 55 W/m2 of radiating panel during the night; during the day the water in the hot water-storage tank was heated from 24 °C to 62 °C at a rate of 96 W/m2. The system was also able to cool the room at a rate of 120 W/m3. The results thus confirmed that it is entirely plausible to design an entirely passive system, that is, without the use of any moving mechanical equipment such as pumps and active controls, for both room-cooling and water-heating. It is thus concluded that a passive night-sky radiation cooling/heating system is a viable energy-saving option and that the theoretical simulation, as presented, can be used with confidence as an energy-saving system design and evaluation tool.en_ZA
dc.description.urihttps://journals.assaf.org.za/index.php/jesa/article/view/1550
dc.format.extent15 pages : illustrationsen_ZA
dc.language.isoen_ZAen_ZA
dc.publisherUniversity of Cape Town, Energy Research Centreen_ZA
dc.subjectRadiation warning systemsen_ZA
dc.subjectSolar radiationen_ZA
dc.subjectRenewable energy sourcesen_ZA
dc.subjectCooling systemsen_ZA
dc.titleModelling and testing a passive night-sky radiation systemen_ZA
dc.typeArticleen_ZA
dc.description.versionPublisher's version
dc.description.versionAuthors retain copyright


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