Install Instructions

20
Balancing the Airflows
Balan cing the airflows 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 airflows
are not properly balanced, the following issues may occur:
 A positive or negative pressure in the house
 HRV not operate at its maximum efficiency
 The unit not defrost properly
Airflow Measuring Gauge
A digital manometer is a suitable instrument for the balancing of
airflows.
99-BAL-KIT Airflow Balancing Kit
Kit includes a digital manometer, pitot tube, hose and tool bag.
Figure A
Digital Manometer
 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
Dimensional Drawing for 205 Model
Note: Front clearance of 25 in (635 mm) is
recommended for servicing unit. All ducts
use 6 in (150 mm) oval collars, balancing
dampers are located on all collars.
Top View
Fresh
Air From
Outside
Fresh
Air To
Inside
Stale
Air From
Inside
Stale
Air To
Outside
Motorized
Impeller
Recirculating
Defrost
Damper
Removable
Heat Recovery
Core
33 5/8 in (854
mm)
Filter
18 3/4 in (476 mm)
Front View
Condensate Drain
15 in (381 mm)
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