Two Airflows, One Biosafety Cabinet | Class II Type A2
A Class Two Type A2 biosafety cabinet needs both inward air at its opening and filtered downward air over the work area. These airflows do different jobs.
Follow the air through the process
Room air enters at the front grille
The blower draws room air inward at the lower opening. The front grille collects this inflow and carries it beneath the work surface.
The return goes around the work surface
Air rises through the rear plenum toward the blower. It does not pass through the solid worktop. That hidden return passage closes the route.
The filtered supply comes down
Part of the blower discharge passes through the supply HEPA filter and moves downward over the work area. Front and rear grilles collect the returning air.
Exhaust balances incoming room air
Another branch passes through a separate exhaust HEPA filter. The balance between inflow, downflow and exhaust matters. More fan speed is not automatically better containment.
Airflow function
- In the cabinet air-handling plenum, driving the balanced inflow, filtered downflow and exhaust routes.
- A controllable backward-curved centrifugal family can be evaluated against supply and exhaust filter resistance. Cabinet geometry and controls determine how total blower flow divides between the required routes.
What can change the result
- A grille blockage or incorrect flow balance can change the intended cabinet air pattern.
Start with the complete air path
Share your layout and the information you already have. Unknown values can be identified before a configuration is selected.
Match the fan to this air path
LONGWELL EC backward-curved families can be considered during suitable cabinet development. Match filter resistance, controls and the required airflow balance. Protection must be verified on the complete cabinet; a fan photograph proves no biosafety certification.
Where it sits
In the cabinet air-handling plenum, driving the balanced inflow, filtered downflow and exhaust routes.
Why consider this configuration
A controllable backward-curved centrifugal family can be evaluated against supply and exhaust filter resistance. Cabinet geometry and controls determine how total blower flow divides between the required routes.
Check the result in your equipment
Discuss your cabinet blower duty
Send inflow and downflow duty, supply and exhaust filter resistance, cabinet controls, alarms and validation. Ask LONGWELL to review a suitable configuration, fan curve, drawing and control details. A layout or existing fan model can start the review.
A layout, installation photos or your existing model is enough to start the discussion.