Design of an individually controlled system for an optimal thermal microenvironment

Individually controlled microenvironment has potential to satisfy more occupants in a space compared to a total volume uniform environment typically used at present. The performance of an individually controlled system comprising a convection-heated chair, an under-desk radiant heating panel, a floor radiant heating panel, an under-desk air terminal device supplying cool air, and a desk-mounted personalized ventilation as used and identified by 48 human subjects was studied using a thermal manikin at room temperatures of 20 degrees C, 22 degrees C and 26 degrees C. At a room air temperature of 20 degrees C, the maximum whole-body heating effect of the heating chair, the under-desk heating panel, and the floor heating panel corresponded to the effect of a room temperature increase of 5.2 degrees C, 2.8 degrees C, and 2.1 degrees C, respectively. The effect was 5.9 degrees C for the combination of the three heating options. The higher the room air temperature, the lower the heating effect of each heating option or heating combination The. maximum whole-body cooling effect of the tested system was only -0.8 degrees C at a room air temperature of 26 degrees C. The heating and cooling capacity of the individually controlled system were identified. These results, analyzed together with results obtained from human subject experiments, reveal that both the heating and the cooling capacity of the individually controlled system need to be increased in order to satisfy most occupants in practice. (C) 2009 Elsevier Ltd. All rights reserved.