| 摘要 |
PURPOSE:To enable to prevent an inner surface of a room wall from dewing, by a method wherein a dew sensor is fixed to a position on an indoor side of a main body of a ventilating fan provided with a blower so that the blower is made to start based on a detecting signal of the dew sensor, through which ventilation of the inside of the room is started prior to generation of a dew on the inner surface of the room wall. CONSTITUTION:A voltage variation corresponding to detected humidity by a dew sensor 17 is applied to a comparison circuit 22 as a detected signal by a signal voltage generating circuit 21, and a motor 9 is electrified by making a relay 24 act when the detected signal becomes more than a reference voltage value to be applied to the comparison circuit 22 from a reference voltage generating circuit 20, that is, when a matter that the dew sensor 17 itself is dewed is detected by the sensor 17, through which a blower 8 is made to start. As the dew sensor 17 is apt to be influenced by an atmospheric temperature when a temperature of the outside D of a room is lower than that of the inside C of the room, the dew sensor 17 losts no time in generating a dew prior to dewing on an inner surface of a room wall A, by detecting which the blower 8 is started. When dew water is evaporated to dryness, operation is stopped. |
