| 摘要 |
PURPOSE:To enable an intake of outdoor air required for performing a ventilation of the indoor with a simple arrangement by a method wherein the number of the persons entering or exiting a room is calculated and a volume of outdoor air to be taken can be taken. CONSTITUTION:In case that a person enters a room through an entrance 1a, oppositely faced infrared rays 18a and 20a fed by the light transmitting means 18 and 20 are closed in sequence, and the light receiving means 19 and 21 generate the output ''H'' in sequence. In reference to an order in which the outputs from these light receiving means 19 and 21 become ''H'', an entering or exiting of a person into or out of the room is judged by a device 22 for calculating the number of persons staying in the room, the number of persons passing is detected in reference to the number of occurrence and then the number of persons staying in the room is calculated. The result of calculation is produced at the outdoor air volume calculation circuit 24 of the intake air volume control circuit 23, a required volume of surrounding air per one person predetermined is multiplied to calculate a required volume of outdoor air. An electric motor 12 for a damper is controlled through a dameper opening degree control device 25 in reference to the calculated volume of outdoor air required. |
