An ergonomics investigation into human thermal comfort using an automobileseat heated with encapsulated carbonized fabric (ECF)

This report presents the results of an ergonomics investigation into human thermal comfort using an automobile seat heated with an encapsulated carbon ized fabric (ECF). Subjective and objective thermal comfort data were recor ded while participants sat for 90 min in a heated and a non-heated automobi le seat in an environmental chamber. Eight male participants each completed eight experimental sessions in a balanced order repeated measures experime ntal design. The conditions in the chamber were representative of a range o f cool vehicle thermal environments (5, 10, 15 and 20 degrees C; in the 20 degrees C trial participants sat beside a 5 degrees C 'cold wall'). Partici pants in the heated seat condition used the heating controller with separat e temperature control over the back of the seat (squab) and bottom of the s eat (cushion) in an effort to maintain their thermal comfort while wearing the provided clothing, which had an estimated insulation value of 0.9 Clo. The trials showed that participants overall sensations remained higher than 'slightly cool' in the heated seat at all temperatures. Participants' over all discomfort remained lower (i.e. more comfortable) than 'slightly uncomf ortable' at temperatures ranging down to nearly 5 degrees C in the heated s eat. Hand and foot comfort, sensation and temperature were similar in both seats. Asymmetric torso and thigh skin temperatures were higher in the heat ed seat although no significant discomfort was found in the front and back of the torso and thigh in either seat. Participants reported no significant difference in alertness between the control and heated seat.