Application of a Thermal Manikin to Evaluate Heat Loss Rates from People caused by Variations in Air Velocity and Air Temperature

Abstract

Heat loss monitoring from a thermal manikin was undertaken representing an occupant in a classroom during a lesson period of 80 minutes in which the room temperature was increased from 21 to 24°C for various airflow velocity configurations. A group of subjects was exposed to various conditions of temperature and airflow rate so that the impact of these variations on their surface/skin temperature could be determined. It was found that skin temperature remained stable and close to 34°C for all conditions of exposure. Thus, over the temperature and air velocity range considered, these new findings verified the suitability of using a thermal manikin, set to steady uniform surface temperature, to determine the heat loss characteristics from occupants subjected to intermittent velocity variation. When the manikin was exposed to a high velocity pulse, the heat loss from the whole body increased by 10% while the heat loss from exposed areas (hands and face) increased by 20 % (when compared to no velocity pulse). After the 80 minutes monitoring period, the total energy loss from a manikin exposed to velocity variations was 2% higher than when exposed to constant low velocity.