At last! A durable convection cover for atmospheric window radiative cooling applications.

Enhanced cooling of surfaces by radiative heat loss through the 8-14 micron atmospheric window was investigated using commonly available materials. Zinc sulphide was found to be a durable substance suitable as a convection cover. With respect to polyethylene, the most commonly used proof-of-concept convection cover in research to date, ZnS is orders of magnitude stronger, impervious to damage by UV, effectively inert and in practical thicknesses is more transparent in the 8-14 micron waveband. Use of this window material with a previously proposed selective radiator material, a form of anodised aluminium that reflects radiation at wavelengths shorter than 8 microns allows for the economical production of an effective selective radiator system. Measurements were made on simple radiator plates and convection covers. The principal aim of this project was to identify a durable cover, rather than investigate or optimise a novel selective radiator surface.