RADIATOR-AIR HEAT EXCHANGER INCORPORATED IN BUILDING DESIGN FOR PASSIVE AND LOW ENERGY COOLING IN THE TROPICS
Authors: Dan, P.D. ; Aynsley, R.M.
Investigation of nocturnal cooling on both exposed and wind-screen metallic radiators, with and
without air as working fluid, has been experimentally conducted at James Cook University of
Australia. A warm and humid tropical region, summer nights in the region are typically calm and with a
high level of humidity. Experimental results indicate that night-time cooling is possible in the tropics,
provided that the sky is not overcast. Considering the radiators acting as the roof of the building,
passing air underneath insulated roofs would be a way to transfer the cool energy from the sky into
the building during summer nights. In this paper, based on the experimental results, mathematical
models for the exposed and wind-screen radiators are presented, with and without air passing
underneath as working fluid. In humid climates, the formation of dew on radiator surfaces at night
significantly affects cooling performance. Dew formation is taken into account in these models, and
this is what makes the modelling in this paper different from those in drier climates. From the models,
prediction of radiator surface temperature and exit air conditions may be made for other similar
climates, using data available from the local Bureau of Meteorology.