Thermal Comfort Zones for Helium Oxygen Atmospheres at Reduced Pressures

摘要

Thermal conductivity for a helium-oxygen mixture is 2.5 times greater than the conductivity of a nitrogen-oxygen mixture at 7 psia. A direct result of this difference is that the convective heat loss from man is higher in a helium atmosphere. Therefore, thermal comfort zones in helium should show an elevated comfort range. Measurements of human comfort zones at pressures of 5, 7 and 10 psia using a random walk technique were made in the Space Cabin Simulator. Air velocities, clothing, and atmosphere diluents were systematically varied. The data show that the mid-point of the comfort range for the clothed subject is highest for He-O2 at 7 psia and lowest for N2 - O2 at both 5 and 7 psia; He-O2 at 5 psia mid way between these extremes. (Author Modified Abstract)