| 摘要 |
A fan, especially for the conveyance of the combustion air in a motor vehicle heating system, provides for adjusting of its output, with an efficiency that is as high as possible, and little operating noise. The fan, which preferably is a ring-duct fan, has a by-pass duct connected in by-passing relationship to the exit of the fan, with the by-pass duct containing an adjustable throttling member. In accordance with a preferred embodiment, the by-pass duct leads back into the intake duct of the fan. |
