| 摘要 |
PURPOSE:To keep inner air clean at all times by introducing outer air to carry out ventilation when the inner air pollution is heavier than the outer air pollution while, on the other hand, cleaning the inner air in accordance with the polluted degree of the inner air when the outer air pollution is heavier is than the inner air. CONSTITUTION:The detected outputs of a first smoke sensor 1 and a second smoke sensor 2 for detecting the polluted degree of outer air and inner air respectively are inputted into a level judging means 8, in which the magnitude of the detected outputs between the first and second smoke sensors 1, 2 and the detected output of the second smoke sensor 2 are compared with their reference values respectively and judged. And, the output of the level judging means 6 is inputted into a driving control circuit 9, from which control signals necessary for a control damper 4, an exhaust damper 6, and an air cleaner 5 are outputted. In this case, when, e.g., the output of the first smoke sensor 1 is higher than the output of the second smoke sensor 2 with the output of the second smoke sensor 2 being higher than the reference value, the exhaust damper 6 is closed while the control damper 4 is switched over to an inner air circulating position. |
