Clothing ventilation, vapour resistance and permeability index: changes due to posture, movement and wind

Laboratory assessment of cold weather clothing

“…The second method, developed by Lotens and Havenith (1988), uses a diluted tracer gas (usually Argon), that is blown into the microclimate in a continuous stream, and the steady state microclimate concentration is sampled, from which the ventilation (volume per time) can be calculated directly (Havenith et al, 1990(Havenith et al, , 2003. This method has been shown to be repeatable and accurate, if the tracer gas is distributed equally over the microclimate regions.…”

“…Such an analysis (see Holmér and Elnas 1981, Havenith, 1990 for details) allows the calculation of the effective heat and vapour resistance of the clothing, including all effects of movement and wind. Unfortunately this is a very time consuming measurement, and therefore costly.…”

Effects of wind and clothing apertures on local clothing ventilation rates and thermal insulation

“…They found that the ventilation of the upper site contributed heavily to the overall ventilation. 2,3,6 Ueda et al used the Crocford's unsteady state method to investigate the regional VR of several working jackets.…”

“…[3][4][5][6][7] Considerable work has been carried out for studying the impacts of wind and garment apertures on garment TI and VR. [3][4][5][8][9][10][11] Havenith et al studied the effects of wind on ventilation and found that wind impacted clothing ventilation significantly. 3,4 And later Havenith et.…”

“…[3][4][5][8][9][10][11] Havenith et al studied the effects of wind on ventilation and found that wind impacted clothing ventilation significantly. 3,4 And later Havenith et. al.…”