Commissioning Instructions

Before You Begin
Loop Tuning Procedures
17
Siemens Industry, Inc. Start-up Procedures 140-1342
Restricted 2015-11-09
Exhaust Flow Accuracy Verification
This section presents the steps for verifying the exhaust flow accuracy.
NOTE:
It is recommended that this procedure be performed with the balancer so that the flow
coefficient is coordinated with the measured exhaust flow.
Verify the exhaust flow as follows:
1. Move the sash to an open position. Using a hand-held air velocity meter, perform a
grid measurement of the face velocity. (Divide the face of the fume hood into 1’ × 1’
squares.) Calculate the average face velocity as shown in Figure
Grid
Measurement of Face Velocity
.
2. Take the average measured face velocity and face area to determine the volume of
air exiting the hood. Use the calculation shown below:
CFM = ((Average measured face velocity) x (Open area of the hood))
Start-up is now complete. Set STARTUP MODE to 0, to enable the FHCs full
functionality.
Calculating Average Face Velocity