Abstract
Central-exhaust ventilation systems operate 24 hours, and exhaust formaldehyde gas or volatile organic compounds. For such systems in newly constructed houses, door undercuts are often applied as the exhaust opening of bed rooms. However, in order to exhaust CO_2 and humidity generated by occupants in bed rooms efficiently, installing an opening in the vicinity of the top of the door might be more effective than that in the vicinity of the door undercut. To compare and confirm which of the locations for the opening is more suitable, authors have examined air flow distribution, temperature distribution, and CO_2 concentration distribution of a bed room during a winter night by CFD simulation. It was found that installing the opening in the vicinity of the top of the door is more effective than under cut, and existing ventilation design manuals should introduce the opening in the vicinity of the top of the door.
