Radiative cooling and frost formation on surfaces with different thermal emittance: theoretical analysis and practical experience

Radiative cooling power was computed as a function of the emittance c, of an exposed surface, air temperature, humidity, etc. from the LOWTRAN 5 code. Meteorological data were then used to make semiquantitative estimates on how often frost will form on a surface with given epsilon(s). Practical tests, using SnO(2)-covered glass with epsilon(s) approximately 0.2, demonstrated that a low-emittance coating can prevent frost formation and maintain transparency of a window exposed to the clear sky.