Other influences on comfort

Fanger (1972) has investigated non-environmental effects and concluded the following, for similar standards of clothing and activity. National and geographical influences are negligible and there are no seasonal effects. There is, apparently, no difference between the comfort requirements of the elderly and young adults, but it must be remembered that elderly people are less active and this implies higher temperatures are needed. It seems that women prefer a temperature 0.3 K greater than men but on his experimental evidence this was not statistically significant at the 5 per cent level. On the other hand, women seem more sensitive to small variations from an optimum temperature and, of course, are more lightly dressed, suggesting the need for a higher temperature in the practical case. Bodily build has little significance for sedentary activities beyond fat adolescence, young adults prefer 0.2K less whilst the menstrual cycle has no significance for comfort temperatures. The little work that has been done on ethnic influences suggests they are insignificant but the intake of food does have a bearing: the optimum comfort temperature could be decreased by as much as IK for some hours after a heavy, protein-rich meal. Although the deep tissue temperatures have a natural cycle of variation over 24 hours of between 0.3 K and 0.5 K with a maximum before sleeping and a minimum some while before waking, this has no significant effect on comfort.

Thermal transients do not have much influence provided the mean value of temperature is reasonably constant at a comfortable value. Furthermore, it has been well established by Glickman et al. (1947) and (1949), Hick et al. (1953) and Inouye et al. (1953) and (1954) that when a person walks from a hot outside environment into a room conditioned at a comfortable but relatively low temperature there is no adverse physiological effect. In other words, there is no such thing as ‘shock effect’. The human body is resilient and acclimatisation is rapid.

Psychological influences have been examined by Rohles (1980), who has suggested that these are very short-term effects: the presence of warmer looking furnishings, for instance, would not give a long-term influence on comfort, neither would the setting of a thermostat that implied an air temperature different from that actually present. Colour is of no significance according to Berry (1961). Psychological trivia of this kind can be totally disregarded as significant factors for sustained thermal comfort.

Posted in Air Conditioning Engineering

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