AN EVALUATION OF THE WIND CHILL FACTOR - ITS DEVELOPMENT AND APPLICABILITY

The wind chill factor has become a standard meteorologic term in cold climates. Meteorologic charts provide wind chill temperatures meant to represent the hypothetical air temperature that would, under-conditio ns of no wind effect the same hear loss from unclothed human skin as d oes the actual combination of air temperature and wind velocity. As th is wind chill factor has social and economic significance, an investig ation was conducted on the development of this factor and its applicab ility based on modern heat transfer principles. The currently used win d chill factor was found to be based on a primitive study conducted by the U.S. Antarctic Service over 50 years ago. The resultant equation for the wind chill temperature assumes an unrealistic constant skin te mperature and utilizes heat transfer coefficients that differ markedly from those obtained from equations of modern convective heat transfer methods. The combined effect of these two factors is to overestimate the effect of a given wind velocity and to predict a wind chill temper ature that is too low.