Laboratory Exhaust Calculator

Calculate exhaust requirements for laboratory fume hoods and safety cabinets per ASHRAE 110 and ANSI Z9.5 standards.

Width of the fume hood face opening.
feet
Height of the fume hood face opening (sash position).
feet
Required face velocity: 80-120 FPM typical, 60-100 low flow.
FPM
Total number of fume hoods in the space.
qty
Percentage of hoods in simultaneous use (0.6 to 1.0).

Results

Single Hood Face Area-ft²
CFM per Hood-CFM
Total System CFM-CFM
Design CFM with Diversity-CFM
References: ASHRAE 110: Method of Testing Performance of Laboratory Fume Hoods; ANSI Z9.5: Laboratory Ventilation; ASHRAE Handbook - HVAC Applications Chapter 16