Initial heating in cold cars
report
During the initial minutes after entering a cold car, people feel uncomfortably cold. Six different warming systems were investigated in a small car in order to find out how to improve the feeling of comfort using 16 volunteers. The methods were: no additional warming next to a standard heating system in the car (1), heat pad in the back (2), heat pad on sun shield (3) heat pad on steering wheel (4) infra-red heating directed to the head (5) infra-red heater directed towards the hands (6). Body core and skin temperatures were measured as well as thermal comfort and thermal sensation of the hands, head and body.
All heating conditions increased ambient car temperature above the control condition. Steer (4) and IR hand heating (6) were beneficial for the thermal sensation of the hand. Thermal sensation of the head was rated highest in the IR head condition (5). The chair condition (2) also scored quite well on heat thermal sensation, but mainly after the first 5 min. Overall thermal sensation was rated highest in the chair condition (2). The control (1) and sun shield (3) conditions were rated lowest, mainly after the first 5 min. Subjects indicated they hardly noticed the sun shield heating. Subjects felt most comfortable in the chair (2) and IR head condition (5).
Regression analyses indicated that thermal comfort is related quite well to thermal sensation, especially of the total body. Thermal comfort and thermal sensation are poorly predicted by core and skin temperatures.
It can be concluded that chair and IR head heating are most beneficial for overall thermal sensation and comfort, the latter working on a shorter term than the former. This result is relatively independent of differences in body temperatures.
All heating conditions increased ambient car temperature above the control condition. Steer (4) and IR hand heating (6) were beneficial for the thermal sensation of the hand. Thermal sensation of the head was rated highest in the IR head condition (5). The chair condition (2) also scored quite well on heat thermal sensation, but mainly after the first 5 min. Overall thermal sensation was rated highest in the chair condition (2). The control (1) and sun shield (3) conditions were rated lowest, mainly after the first 5 min. Subjects indicated they hardly noticed the sun shield heating. Subjects felt most comfortable in the chair (2) and IR head condition (5).
Regression analyses indicated that thermal comfort is related quite well to thermal sensation, especially of the total body. Thermal comfort and thermal sensation are poorly predicted by core and skin temperatures.
It can be concluded that chair and IR head heating are most beneficial for overall thermal sensation and comfort, the latter working on a shorter term than the former. This result is relatively independent of differences in body temperatures.
Topics
TNO Identifier
470993
Publisher
TNO
Collation
29 p. (incl. bijlage)
Place of publication
Soesterberg
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