Prof. Ing. Karel Kabele, CSc.

Problems following the application of optimal operative temperatures estimated on the basis of PMV and the necessity to apply correct values into the new Czech Government Directive No. 523/2002 Code led to experiments based on the physiological human body response instead of on solely man’s feelings in a defined environment. On the basis of experiments on 32 subjects (university students) it has been possible to estimate: a) total balance of hygrothermal flows between the human body and environment, b) the optimal operative temperature as a function of the subject’s activity, c) the thermoregulatory range for each optimal operative temperature, i.e. maximal (category Cmax) limited by the beginnings of sweating, minimal (category Cmin) limited by the beginnings of shivering (category C can be applied to the natural ventilated buildings), optimal (comfort level – category A) defined by time constant 0.368 (can be applied to air conditioned buildings) and submaximum (decreased comfort level – category B) defined by time constant 0.632 (can be applied to buildings with basic air conditioning systems).