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AIRFLOW ADJUSTMENT & BALANCING
BALANCING THE AIRFLOWS IS CRUCIAL TO ENSURE OPTIMAL OPERATION OF THE UNIT. IF THE AIRFLOW IS NOT PROPERLY BALANCED, THE
FOLLOWING ISSUES MAY OCCUR:
• SIGNIFICANT POSITIVE OR NEGATIVE PRESSURE INSIDE THE HOUSE
• UNIT’S EFFICIENCY MAY BE NEGATIVELY AFFECTED
• UNIT’S DEFROST MAY NOT WORK EFFECTIVELY
• CAN LEAD TO AIR LEAKS OR BACKDRAFTING OF ANY COMBUSTION APPLIANCES.
The airflow adjustment and balancing procedure consists of adjusting the fresh airflow to make sure it meets the requirements for the building and then
balance the system to make sure there is an equal amount of stale air being exhausted. In the case that the airflow is not exactly the same, it is
recommended to have a higher stale airflow of up to 10% in colder climates to ensure that the temperature of the fresh airflow coming from the outside
is as close to the room temperature as possible.
GENERAL PREPARATION:
Before performing the adjustment and balancing for unit, make sure to check the following:
• Seal all the ductwork
• Fully open all dampers (if present)
• Turn off all other exhaust appliances such as range hood, dryers, bathroom fans, etc.
• If performing balancing during cold weather, make sure the unit is not operating in defrost mode.
• If the installation type is Simplified or Partially Dedicated, make sure that the furnace/air handler blower is operating at normal speed during
the balancing sequence.
• When reading with a mechanical type manometer (Magnehelic), make sure the manometer is placed on a level surface
For optimal performance, HRV unit should be re-balanced after a major renovation or after the installation of extra grilles or registers.
•
In cold climates, continuous excessive positive pressure inside the house may drive moisture inside the external walls of the
house. Moisture present inside the external wall may condense if the outside temperature is cold enough and can cause damage
to structural components. A symptom of excessive positive pressure inside a house is frozen door locks.
• Continuous excessive negative pressure can have undesirable effects. In some geographic locations, negative pressure can
increase the infiltration of soil gases such as methane and radon. Negative pressure is also undesirable where combustion
equipment is present and may cause back drafting of the combustion gases.
ADJUSTING AIRFLOWS USING INTEGRATED BALANCING SYSTEM
Adjustable dampers are integrated into the Fresh Air to Building and the Stale Air to Outside duct connections. Those dampers replace the installation of
separate back draft and balancing dampers in the duct line.
The integrated dampers are preset at the fully opened position. In order to reduce the amount of airflow, turn the adjustable lever using a flat screw driver
by turning it counter clock wise. Turning the lever clockwise may damage the plastic screw head. Follow the balancing steps to properly adjust the airflow.
