| 摘要 |
PURPOSE:To obtain a ventilation fan which makes less noise at its air outlet and whose delivery port is easily connected to a duct. CONSTITUTION:A ventilation fan includes an external box 15 where a fan 18 is housed, a duct joint 23 which is connected to an air outlet 17 of the external box 15, and a duct 26 to be connected to the duct joint 23. The duct Joint 23 on the delivery port 17 side is larger than the delivery port 17 in diameter and sound-absorbing material 27 is attached around the delivery port 17. In addition, a shoulder part 24 is provided at the end of the duct joint 23 so that the duct 26 is connected horizontally. Air flow noise at the delivery port 17 is absorbed by the sound-absorbing material 27 and noise is diminished. Further, the shoulder part eliminates difference in level at the joint between the duct 26 and duct joint 23, resulting in an improvement of workability in taping work, etc. |
