Princeton University: „Revisiting radiant cooling: condensation-free heat rejection using infrared-transparent enclosures of chilled panels“
Eric Teitelbaum, Adam Rysanek, Jovan Pantelic, Dorit Aviv, Simon Obelz, Alexander Buff, Yongqiang Luo, Denon Sheppard & Forrest Meggers (2019) Revisiting radiant cooling: condensation-free heat rejection using infrared-transparent enclosures of chilled panels, Architectural Science Review, DOI: 10.1080/00038628.2019.1566112
Unter der Leitung von Mr. Eric Teitelbaum (Princeton University) fand die Grundlagenuntersuchung der eingesetzen Technologien und praxisnahe Tests in singapurionischem Klima statt. Die spektrale Analyse der High-Tech Membrane, themodynamische Betrachtungen und die Detailanalyse der physikalischen Vorgänge waren Arbeitsschwerpunkte.
In this study, we enhance the understanding and design of a radiant cooling technology for outdoor comfort in tropical climates, originally proposed by R.N. Morse in 1963, in this journal. We investigate a type of radiant cooling methodology whereby the cold temperature source is physically separated from the outdoor environment by an insulated enclosure using a membrane transparent to infrared radiation. The enclosure isolates the radiant cooling surface from ambient conditions, allowing the radiant surface to be cooled significantly below ambient dew point temperatures without incurring condensation. For this new study, a Fourier Transform Infrared (FTIR) Spectroscopy analysis on three candidate membrane materials is undertaken and a prototype experimental test panel is fabricated. Our study shows that for a 5°C chilled panel temperature, the exterior membrane surface temperature reaches 26°C in a 32°C / 70% RH environment resulting in an effective mean radiant temperature of 15.8°C. These results provide new evidence in support of Morse’s original proposal, that such panels could provide significant radiant cooling without condensation in humid environments. Radiant cooling products based on the studied technology may offer an ability to provide thermally comfortable conditions in hot environments without the energy required for dehumidification.
KEYWORDS: Radiant cooling, sub dewpoint, thermal comfort, spectral analysis, thermal transparency