| 摘要 |
A ventilation system particularly for use with a fume cupboard of the kind used in laboratories or similar situations including velocity sensors for providing signals to a control system which operates a damper system for selectively regulating the supply of external air to an exhaust duct for maintaining a predetermined air velocity in the fume cupboard. Preferably the sash of the fume cupboard includes drive means for enabling automatic closure of the sash in the event of extended periods of non-use. |
