7
12”
(300mm)
FLOW
COLLAR
FRONT
FRESH AIR
FROM OUTSIDE
STALE AIR
TO OUTSIDE
TEMPORARY
FLOW COLLAR
TEMPORARY
FLOW COLLAR
RIGHT SIDE VIEW
with vertical ducts
RIGHT SIDE VIEW
with horizontal ducts
36”
(914mm)
36”
(914mm)
12”
(300mm)
36”(914mm)
FRESH AIR
FROM OUTSIDE
STALE AIR
TO OUTSIDE
TEMPORARY
FLOW COLLAR
FRONT
BALANCING
DAMPER
BALANCING
DAMPER
BALANCING
DAMPER
A12368
Fig. 9 -- Balancing HRVXXLVU
BALANCING HRV
Balancing intake and exhaust airflow is very important for proper
system operation and optimum performance when applying an
HRV. Unit balancing prevents a positive and/or negative pressure
within the home. Balancing the HRV is done by applying
temporary flow collars and permanent balancing dampers to the
fresh air intake and stale air exhaust ducts (See Fig. 9).
Airflow is determined by connecting a magnehelic gauge to the
temporary flow collar (see Fig. 10). Both flow collars and
magnehelic gauge are included in the accessory start--up balancing
kit.
If supply--air from outside is greater than exhaust--air from the
house, an imbalance can result over pressurizing the home. If
exhaust--air is greater than supply--air, combustion appliances may
back draft, bringing exhaust fumes into the house. A balanced
condition will ensure optimum performance, provide satisfied
customers, and avoid expensive callbacks.
Before proceeding with balancing, all windows, doors, and
fireplace flues should be tightly closed. No exhaust systems such as
range top exhausts, dryer exhaust, fume hoods, bath or roof fans
should be in operation. The forced--air furnace (if used for
circulation) should be operating in continuous fan mode for normal
operating speed.
MAX
MIN
AIRFLOW
DIRECTION
CONVERSION
CHART
MAX
MIN
ZEROING SCREW
FLOW
COLLAR
A98400
Fig. 10 -- Magnehelic Gauge
Balancing Dampers
The dampers for the HRVXXLVU are field supplied and should be
permanently located in fresh--air intake and stale--air exhaust ducts
between HRV and exterior wall (see Fig. 9). Some field
modification may be required to ensure proper installation of
balancing dampers while located in flexible duct. Insulating over
these dampers is strongly recommended after balancing is complete
to prevent condensation problems.
Flow Collar
Flow collars are temporary and should be installed as close to HRV
as possible and in straightest sections of duct to ensure accuracy
(see Fig. 11 and 12). If only 1 flow collar is available, install collar
in stale--air duct of HRV, and record airflow. Next, install collar in
the fresh--air duct and record airflow. If 2 flow collars are available,
it will be much easier to read airflow and properly adjust dampers
to balance unit.
With speed control at maximum speed (high--speed operation) and
continuous air exchange occurring with outside, connect hoses
from flow collar to a magnehelic gauge (see Fig. 10). The gauge
must be leveled and zeroed before use to read accurately. If needle
falls below zero, reverse hose connections.
LOW HIGH
FLOW
A12455
Fig. 11 -- Balancing HRVXXLVU
