LOC’s Bypass Fume Hood provides continuous air flow across the work surface even when the sash is closed. The fume hood features an internal, alternative opening located above the sash. This allows for a constant air volume which allows for change in the hood’s face velocity. In operation, the bypass exhaust system works automatically, in conjunction with the hood sash. The bypass adjustment is made as the sash is opened and closed creating a relatively constant air volume regardless of sash position.
The static pressures listed above are for the hoods only. An appropriate amount will need to be added to this figure to compensate for the pressure drop through the duct system. The total pressure drop through the hood and the duct system must be known to select the proper exhaust blower.