A STUDY OF A CONTROL STRATEGY UTILIZING OUTDOOR AIR TO REDUCE THE WINTERTIME CARBON-DIOXIDE LEVELS IN A TYPICAL TAIWANESE BEDROOM

A CO2 concentration of more than 1000 ppm has been monitored in Taiwan ese bedrooms during sleeping hours in the wintertime. The high indoor CO2 levels were caused by poor ventilation due to insufficient ventila tion rates. This study sought to reduce the wintertime CO2 concentrati on level in a typical Taiwanese bedroom with less outdoor air to maint ain thermal comfort. CO2 was used as an indicator to assess whether an adequate ventilation rate has been obtained to dilute or remove harmf ul pollutants. With the help of the thermal buoyancy effect, the CO2 g enerated in the bedroom was effectively removed by means of less outdo or air. Through computational fluid dynamics simulations, the appropri ate window and transom locations with the corresponding outdoor air su pply volume, as well as the lowest possible outdoor air temperature we re identified. (C) 1998 Elsevier Science S.A. All rights reserved.