Patent US 5,333,953

The present invention provides a method and apparatus for calculating thermal sensitivity and predicted mean thermal sensitivity felt by a person in an environment. According to the apparatus of the present invention, an air temperature Ta, a clothing thermal resistance Icl, and a sensor temperature Tcr of a sensor within the environment are provided as input to an input section of the apparatus. Upon receiving these values, a set temperature calculating section of the apparatus calculates a set temperature .theta..sub.(th). A thermal energy control means supplies thermal energy information H.theta..sub.(th) to a heater so as to heat the sensor in order to maintain the sensor temperature Tcr at the calculated set temperature .theta..sub.(th). An equivalent temperature calculating section then calculates an equivalent temperature Teq.sup.* so that a predicted mean thermal sensitivity PMV.sup.* can then calculated on the basis of the obtained equivalent temperature Teq.sup.*.