Specifications

Systems Integration
Forced Air System
When the Heat Recovery Ventilator (HRV) is installed in
conjunction with a forced air system, the air handler and
the network of ducts associated with it are used to dis-
tribute fresh air inside the building. If this type of system is
used, the main fan of the air handler must operate contin-
uously when the HRV unit is on. Fan interlock can be con-
nected to terminals 6 and 7 on the low voltage terminal
strips left side on the exterior of the unit (for low voltage
Class II circuit only). These terminals are factory connected
to dry contacts (FF) on the microprocessor control board
in the unit control box. The controller makes relay contact
between these terminals when the unit is operating, See
Fan Interlock Switch (FF).
Fresh air from the HRV should be introduced into the re-
turn duct of the air handler at a point no less than 6 feet
[1,829 mm] upstream of the air handler. The duct con-
nection for return air to the HRV should be made on the
return air duct at least 2 feet [610 mm] upstream of the
fresh air duct connection.
Separate Systems
Select locations for exhaust grilles and supply diffusers
to provide effective ventilation and avoid short circuiting
airflows through the space. Adjustable dampers should be
provided at every grille and diffuser to make balancing of
the system possible.
A proper selection of style and size of grilles and diffusers
is required to minimize pressure drop. The velocity of the
airflow should not exceed 400 feet per minute [2 meters
per second] for normal applications.
The duct system should be designed according to the high
speed flow rate of the unit. In order to keep the noise and
pressure drop to a minimum, a maximum air velocity of
1,100 feet per minute [5.6 meters second] should be used
in calculations in duct design. The duct runs should be
kept as short as possible with the minimum amount of el-
bows and transitions. The Manufacturer recommends the
use of smooth radius elbows or square elbows with turn-
ing vanes to achieve maximum performance.
Dampers
An insulated motorized outdoor air damper is included
with the unit with recirculation defrost or exhaust only de-
frost which closes during a frost control cycle or placed in
the ‘Off’ position with power maintained to the unit. Out-
door air damper will remain open if power is disconnected
from the unit while operating in heat recovery mode.
A backdraft gravity damper is supplied with recircula-
tion defrost units to be installed in the exhaust air outlet
duct on indoor units. This damper is necessary to prevent
air from entering the building through the exhaust duct
when the unit is in recirculation defrost mode. See Exhaust
Dampers for Indoor Units for further installation details.
Mount the damper in the exhaust air to outside duct as
shown in Appendix C and Ductwork for fan outlet duct
considerations.
Drains
The drain fittings provided with the unit will accept a ¾”
[19 mm] NPT coupler (supplied by others). The drain line
for the unit must be fabricated on site and connected to
the building main. A loop in the hose or trap in the copper
or plastic pipe must be provided to prevent sewer gases
from entering the unit when connecting to a drain as illus-
trated in Appendix D.
Prime the trap by filling with water before start-up. Check
and clear drains annually. Drainage problems can occur
should drains be inactive and dry out, or due to reduced
water flow caused by buildup of algae. Regular mainte-
nance will prevent these problems from occurring.
IMPORTANT
Consult local building code for plumbing requirements
in your area. If copper pipe is to be used, ensure not to
solder to the ¾” [19 mm] coupler while it is attached to
the plastic drain fitting as deformation may occur. Ensure
adequate slope is present to allow good drainage (mini-
mum ¼” per foot [6 mm per 305 mm]).
VCES-HRV-IOM-1C – HRV600i, HRV700i, HRV1200i
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