The Heat Transmission of Fabrics in Wind

Two samples of overcoating material were tested for heat transmission in wind when an air space under the material was provided. The effect of a wind breaker both under and over the material was observed. The work shows that when a sample has a high permeability to air and does not lie close to the hot plate, there is a very marked differ ence between the results obtained with a wind blowing parallel to the surface and those with the wind striking the surface at 45°. The work also proves that the thermal insula tion afforded by a fabric or combination of fabrics in wind depends on what is underneath the sample and suggests that some purely arbitrary test procedure, specified by a standardizing authority, may be desirable.