Fume Hood Monitor and Controller – User Guide 11 © 2016 CRITICAL ROOM CONTROL
Immediate Valve Control (IVC™) – Sash Sensing
Unlike conventional hood controllers that merely rely on a PI loop to slowly react to changes in
sash position, CRC fume hood controller’s Immediate Valve Control (IVC)™ technology continually
measures sash position and current CFM at a rate of 5 times per second to immediately react to
a change in sash position and instantly drive our valve to the correct valve position to maintain
face velocity.
CRC’s IVC™ algorithms utilize an air flow table that is created with an automated process that
takes less than 20 seconds during the commissioning of the fume hood.
To create this table, simply click on the “Valve Table” button on the Exhaust Input Setup screen
to show the “Valve Air Flow Table” screen.
To setup / enable IVC, first confirm that the exhaust flow is running at the lowest static pressure
to be used during operation, then press the “Pop Table” button to auto populate the flow values
of the hood’s exhaust valve. After pressing this button, the controller automatically records the
valve’s flow rate for different key actuator positions. This process takes approximately 20 seconds
to complete. When finished, the table status should read “NO ISSUE”.
To disable IVC, click the “Reset Table” button.
Please note the following:
• Changing the valve’s “K Factor” will NOT effect the table. Once the table is created – the
table values will automatically adjust to changes in K Factor.
• For optimized performance, the exhaust flow should be running at the lowest static
pressure to be used during operation of the hood before pressing the “Pop Table”
button.
• If “Zero Valve” status is displayed, then go through the Valve Zeroing process outlined
on previous page before repopulating the valve’s airflow table.
To Next Page
Loading...
Need help?
General
