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Zonex Systems zone dampers are used in cooling / heating systems to provide room by room zone control. The
damper is provided with a zone actuator. Each zone damper is controlled by a zone thermostat. More than one
damper can be controlled by one zone thermostat.
2 WIRE ZONE DAMPERS
Zonex Systems round low pressure zone dampers can be used for
systems up to 5 tons with a maximum differential static pressure of 0.5”.
These are two position, spring open, power close dampers for very simple
operation. All sizes are designed with rolled-in stiffening beads for easy
installation. A hat section supports a synchronous 24V AC 60Hz 12VA
motor and terminal board. A red LED will be illuminated on the damper
terminal board to indicate when the damper is being powered closed. The
LED will remain on when the damper is fully closed and cycle off when the
damper is opening or in the full opened position. Since this is a spring
open damper, in the event of power failure, the damper fails to the full
open position.
ROUND LOW PRESSURE ZONE DAMPERS (TRX diam)
LOW PRESSURE (TRX diam)
LOW PRESSURE (TREX W x H) RECTANGULAR
DAMPER
Zonex Systems rectangular low pressure zone dampers can be used for
systems up to 5 tons with a maximum differential static pressure of 0.5”.
These are two position, spring open, power close dampers. The damper
is a single blade type that slips into a 2-1/2” wide cutout in the existing
duct and attaches with screws via a duct mounting plate. The duct mount-
ing plate is 5” wide. A red LED will be illuminated on the damper terminal
board to indicate when the damper is being powered closed. The LED will
remain on when the damper is fully closed and cycle off when the damper
is opening or in the full opened position. Since this is a spring open
damper, in the event of power failure, the damper fails to the full open
position.
RECTANGULAR LOW PRESSURE ZONE DAMPERS (TREX W x H)
SIZING ZONE DAMPERS
If the ductwork already exists, simply size the damper to fit the ductwork. For new systems or retrofit jobs:
A. Determine CFM from heat gain or loss calculations.
B. Select damper size using either the round capacities chart, the rectangular capacities chart or
by using a duct sizing table or calculator.
C. Select a Zonex Systems damper to fit the duct size selected for that zone.
Make sure your zone dampers match the type specified in the table showing Maximum Differential Pressure.
INSTALLATION NOTES
1. Do not exceed 700 FPM in a register/diffuser branch duct.
2. If a damper is installed within 3 feet of a register/diffuser, install sound attenuating flex duct between
damper and outlet.
3. Zone dampers should be preceded by 2’
−
4’ of straight pipe where possible.
4. In attic installations and high humidity areas, the Zonex Systems damper should be insulated along with
the ductwork. The hat section on the round damper is delivered with insulation between the hat section
and pipe. Therefore, insulation should be applied to the round pipe and be butted against the hat section
(do not insulate the motor). The motor generates enough heat so that no condensation will develop on it.
5. Remember to allow a 16” gap in the duct for heavy duty rectangular CD dampers.
6. Low pressure rectangular dampers slide into a 3” wide cutout in the side of the pre-existing duct
work.
7. Minimum open and close positioning is field adjustable on the actuator. The damper is shipped from the
factory to close 100%.
NOTE: Dampers should not be installed with motor upside down in the 6:00 position.
