The effect of rowing headgear on forced convective heat loss and radiant heat gain on a thermal manikin headform.
Both radiant and forced convective heat flow were measured for a prototype rowing headgear and white and black cotton caps. The measurements were performed on a thermal manikin headform at a wind speed of 4.0 m . s(-1) (s = 0.1) in a climate chamber at 22.0 degrees C (s = 0.05), with and without radiant heat flow from a heat lamp, coming from either directly above (90 degrees ) or from above at an angle of 55 degrees . The effects of hair were studied by repeating selected measurements with a wig. All headgear reduced the radiant heat gain compared with the nude headform: about 80% for the caps and 95% for the prototype rowing headgear (P < 0.01). Forced convective heat loss was reduced more by the caps (36%) than by the prototype rowing headgear (9%) (P < 0.01). The radiant heat gain contributed maximally 13% to the net heat transfer, with or without headgear, showing that forced convective heat loss is the dominant heat transfer parameter under the chosen conditions. The results of the headgear - wig combinations were qualitatively similar, with lower absolute heat transfer.
Bogerd
Cornelis P
CP
EMPA/Swiss Federal Laboratories for Materials Testing and Research, St. Gallen, Switzerland.
Brühwiler
Paul A
PA
Heus
Ronald
R
D001833:Body Temperature Regulation / Q000502:physiology*; D006257:Head / Q000528:radiation effects*; D006358:Hot Temperature; D008348:Manikins; D009426:Netherlands; D011481:Protective Clothing; D012767:Ships; D013177:Sports