Installation manual

• A positive or negative pressure may occur in the house
• ERV may not operate at its maximum efficiency
Air Flow Measuring Gauges
The magnehelic gauge and the digital manometer are
suitable instruments for the balancing of air flows.
A magnehelic gauge with a scale of 0 to .25" w.c. is
suitable for accurately measuring air duct velocity.
The value on the gauge will be velocity pressure. A
digital manometer requires the ability to display
differential pressures at 3 digits of resolution.
Gauge Attachments
When sampling an air flow, various attachments are
available for use on a magnehelic gauge or digital
manometer.
Consult with your Lifebreath Distributor for available
options such as a pitot tube and flow measuring
station.
The following illustration shows a magnehelic gauge
with a scale of 0 to .25" w.c. with a pitot tube
attachment. This combination will measure the system
air velocity pressure accurately, regardless of the duct
size or shape (either round or rectangular).
Balancing Preparation
Prior to performing the air balancing procedure,
perform the following steps:
• Seal the ductwork system
• Confirm the installation and proper operation of all
the components of the ERV.
• Fully open the balancing dampers.
• Turn off all household exhaust devices (range hood,
clothes dryer, bathroom fans).
• Set the ERV at high speed.
• Prior to balancing the unit, first adjust air flows in
branch lines to specific areas of the house.
• If the outdoor temperature is below 0˚C (32˚F),
ensure the unit is not running in defrost.
• Place the magnehelic gauge on a level surface and
adjust it to zero.
• If the system is a Simplified or Partially Dedicated
installation, operate the furnace/air handler at high
speed.
Balancing the air flows is critical to ensuring that the amount of air introduced from the outside of the building
equals the amount of air exhausted to the outside of the building. If these two air flows are not properly balanced,
the following issues may occur:
Balancing the Air Flows (Applicable of All Models)
M
A
G
N
EH
E
LI
C
DUCT
AIR
FLOW
Pitot tube
High Pressure Side
Low Pressure Side
Magnehelic gauge
Pitot tube and gauge
Continuous, excessive, positive pressure may drive
moist indoor air into the external walls of the building.
Once inside the external walls, moist air may condense
(in cold weather) and degrade structural components
or cause locks to freeze.
Continuous, excessive, negative pressure may have
several undesirable effects. In some geographic
locations, soil gases such as methane and radon gas
may be drawn into the home through basement or
ground contact areas, and may also cause the
backdrafting of vented combustion equipment.
ATTENTION
Magnehelic Gauge with a scale of 0 to .25” w.c.
Pitot Tube Balancing Kit
Part # 99-167—includes Magnehelic Gauge (scale 0 to
0.25” w.c.), Pitot Tube, Hoses, Carry Case and
Instruction page.
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