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Global IFS
Fan Powered Box
FAN POWERED BOX & TERMINAL UNIT
START UP & OPERATION
Air System Balancing
Overview
All ductwork must be complete and connected, and all grilles, filters, access doors and panels must be properly installed to
establish actual system operating conditions BEFORE beginning air balancing operations. Each individual unit and attached
ductwork is a unique system with its own operating characteristics. For this reason, air balancing is normally done by balance
specialists who are familiar with all procedures required to properly establish air distribution and fan system operating
conditions.
These procedures should not be attempted by unqualified personnel.
After the proper system operation is established, the actual unit air delivery and the actual fan motor amperage draw for each
unit should be recorded in a convenient place for future reference such as the inspection, installation, & start-up check sheet, a
copy of which is provided on the back of this manual. Contact the sales representative or the factory for additional copies of
this sheet.
The manufacturer assumes no responsibility for undesirable system operation due to improper design, equipment or
component selection, and/or installation of ductwork, grilles, and other field supplied components.
Air Balancing Procedure
Before Air Balancing the terminal unit, the following general items should be verified
.
1.
The primary fan system is operating at the specified volume, static pressure, RPM and current.
2.
Return filters (if supplied) are clean.
3.
All balancing dampers are adjusted and locked. Dampers downstream of the terminal unit should be proportionally
balanced.
4.
Thermostats are calibrated and operational.
5.
All duct work and connections are free from leaks.
6.
Sufficient duct static pressure is available at the terminal primary air inlet.
7.
All diffusers are installed and adjusted for the proper air pattern.
NOTE:
Since fan powered terminals are typically operating within a pressurized plenum, all flooring tiles must be replaced prior to
verifying outlet flows
.
8. A fan powered terminal unit should never be operated if the downstream duct work has not been installed. A
minimum downstream static pressure resistance of 0.1 in. w.g. is recommended.
9. If field adjustment of the primary air valve should be necessary, follow the appropriate calibration procedures for
the controller type supplied with the unit. If DDC controls are supplied, refer to the control contractor’s
documentation for calibration instructions.
10. Set the thermostat to full cooling. The fan should be on and the primary air valve (if present) at maximum air flow.
Verify the air flow with the sensor tube or pitot tube traverse. Adjust if necessary.
11. The fan volume must be field adjusted with the fan speed controller. Fan curves (available at priceindustries.com)
indicate the volume range of each size unit. Adjust the speed control until the desired air flow is measured at the
outlet.
12. Set the thermostat to full heating. The fan should be on and the primary air valve (if present) at minimum flow.
Verify the primary air volume with sensor taps or pitot tube traverse. Adjust if necessary.
13. Always set the fan volume at full cooling.