| 摘要 |
PURPOSE:To reduce the noise surely even when the speed of air, passing through an air-conditioning duct, is high. CONSTITUTION:An air-conditioning duct 12 guides ventilating air from the ventilating fan 11a of an air-conditioning machine 11. A microphone 13, arranged in the air-conditioning duct 12 near the air-conditioning machine 11, detects the noise from the air-conditioning machine 11. An evaluating microphone 14, arranged in the downstream side of the air-conditioning duct 12, detects the noise of an objective point for control. A controller 16 carries out low ventilating operation prior to stationary operation upon driving the air-conditioning machine 11 to correct the operating coefficient of an operator 16a under the condition of low ventilating operation. Accordingly, the operating coefficient of the operator 16a becomes a coefficient coping with the frequency characteristics of the noise from the air-conditioning machine 11. |
