Impact of individual characteristics - Such as age, gender, BMI, and fitness - on human thermal sensation

A new Human Thermal Model (HTM) has been developed at VTT Technical Research Centre of Finland (VTT) for predicting thermal behaviour of the human body. HTM is based on true anatomy and physiology of the human body, and it estimates human body tissue and skin temperature levels. HTM divides the body into sixteen different body parts each being further sub-divided in realistic tissue layers. The functional tissue layers are also connected to adjacent body parts by a blood circulation system, which has been used for physiological thermoregulation of the whole body. The thermal sensation and thermal comfort estimation methodology by Zhang Hui (2003) is integrated in HTM, allowing much more detailed thermal sensation and thermal comfort index estimations than traditional Fanger's methodology (Fanger 1970). HTM is a module of a non-commercial VTT House building simulation tool, also developed at VTT. VTT House is used for modeling thermal interactions between the human body and the surrounding space by means of finite difference heat balance method, including convective, radiation, and evaporative heat transfer. This integrated method enables the quantitative analysis of the significance of both external (air and surface temperatures, air velocity, and relative humidity) and internal (clothing and metabolic activity level) boundary conditions on thermal sensation and comfort. As a module of the VTT House building simulation tool, HTM can be used for estimating more accurately than before the thermal sensation and comfort of building occupants in transient and non-uniform conditions (Holopainen 2012). This paper aims to evaluate impacts of age, gender, BMI and fitness on human thermal sensation. These results can be utilised in updating design and dimensioning guidelines when balancing energy efficiency and occupant well-being in the future buildings