Specifications

Exhaust Dampers for Indoor Units
An exhaust gravity backdraft damper is included for indoor
units with the recirculation defrost option and shipped
loose for field installation. An exhaust gravity backdraft
damper or a motorized exhaust damper is available as
an accessory for other defrost options or additional use
and shipped loose for field installation. Gravity backdraft
dampers are for horizontal airflow installations only.
Dampers are non-insulated, for installed in duct installa-
tion and are ¼” [6 mm] smaller “outside of frame” than
the duct size listed. An access panel in the duct on the
upstream left hand side (facing the airstream) for the mo-
torized damper is required for access to the actuator and
linkage which is mounted and located in the airstream.
The damper should be mounted sufficiently far enough
downstream from the exhaust fan discharge to avoid sys-
tem effect added pressure losses. A straight length of duct
same size as the unit exhaust discharge and length as indi-
cated in Ductwork followed by the damper and as shown
in Appendix C Note 2 is recommended.
Wiring for the 24V motorized exhaust air damper must
be provided and completed in the field by the Installer. A
separate 24V, 20 VA power supply is required and must
be field supplied for the motorized exhaust damper. Run
the +24V wire connection through the fan interlock con-
tacts on the microprocessor control board or unit terminals
6 and 7 (left side) to break power to the damper when the
exhaust fan is not running as shown in Appendix F for it to
spring return closed.
Ductwork
The supply and exhaust duct connections on the unit are
as follows:
The supply and exhaust ducts connected to outside, as
well as any ducts passing through an unconditioned space,
must have a minimum insulation value of R5. In addition,
a continuous integral vapor barrier over the duct insulation
must be used.
Air balancing dampers are recommended for both supply
and exhaust ducts to allow for adjustment of airflow. Also,
flexible canvas connectors should be installed close to the
unit in the supply duct to the building and the exhaust
duct from the building to reduce noise transmission from
the unit to the building (see Appendix C).
All ports on the 600 and 1,200 cfm units have 1” [25 mm]
flanges to facilitate the installation of the ductwork. Please
note that the outdoor air opening port has a frost control
damper incorporated with it. Ensure that any mechanical
fasteners used to connect the duct do not interfere with
the operation of the damper. Screws can be installed on
the side of the cabinet rather than the flange for this port
only. For port locations see Appendix B.
All ports on the 700 cfm unit have 2” [51 mm] flanges to
facilitate the installation of the ductwork. Please note the
outdoor air opening connection is factory set to be the left
side upper port. It is possible to reverse the operation of
the frost control damper in order to use the port on top of
the cabinet for outdoor air opening connection.
To change the outdoor air opening from the side to the
top use a screwdriver to change the rotation reversing
switch on the actuator. For port locations see Appendix B.
IMPORTANT
Duct sizes are for connection purposes only. Ducts should
be sized to keep noise and pressure drop to a minimum.
IMPORTANT
Straight duct sections minimum of 30” [762 mm] are re-
quired on supply to building and exhaust from the build-
ing to achieve good airflow performance.
Table 1: Exhaust Dampers for Indoor Units
Model
Venmar CES
Part Number
Duct Size
(H x W)
Damper Type
HRV600i
HRV700i
067120
8” x 14”
[203 x 356 mm]
Backdraft (pressure
open/gravity closed)
067121
24V non-insulated
motorized (power
open/spring return
closed)
HRV1200i
067116
8” x 20”
[203 x 508 mm]
Backdraft (pressure
open/gravity closed)
067118
24V non-insulated
motorized (power
open/spring return
closed)
Table 2: Supply and Exhaust Duct Connection Sizes
Unit Duct Size (H x W)
HRV600i or HRV700i 8” x 14” [203 x 356 mm]
HRV1200i 8” x 20” [203 x 508 mm]
VCES-HRV-IOM-1C – HRV600i, HRV700i, HRV1200i
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