Measuring The Airflow Using Station (Grid) Method - SystemAir Fantech SHR 150R Manuel D'installation Et D'utilisation

12
Airflow balancing (Cont'd)
Adjusting airflows
A damper is integrated into the Fresh Air to Building collar. This damper replaces the installation of a separate
damper into the Fresh Air to Building ducting line.
The damper-collar is pre-set in the fully opened position. If the procedure requires a reduction in airflow to
the fresh air duct, simply turn positioning knob located on the side of the collar clockwise until desired airflow
is obtained. The damper position can be determined by the orientation of the pointers situated on the side of
the damper. The damper is fully open when the pointers are towards the top of the collar (as shown in picture)
and fully closed when they are sideways.
Once procedure is completed, install a piece of tape over positioning knob to avoid any tampering by the home owner.
WARNING! DO NOT TURN POSITIONING KNOB COUNTERCLOCKWISE WHEN DAMPERS ARE FULLY OPENED AS DAMAGE MAY OCCUR
TO THE MECHANISM

Measuring the airflow using station (grid) method

1 Cut hole in duct and insert flow measuring
station. Make sure that the flow measuring
station's air direction arrow points in the
direction of the airflow. Secure the flow
measuring station with duct tape.
Minimum
457mm (18")
Measure
here
2 Before taking the reading, make sure that
the magnehelic gauge is level and at 0.
Refer to the flow measuring station's
chart to determine your unit's airflow
velocity.
• To avoid airflow turbulence and incorrect
readings, the airflow velocity should be
measured on a section of steel ducting.
Measure
Reading should also be taken at a minimum
here
distance of 457 mm (18") from the unit or
elbow. Measurement should also be made
Minimum
prior to any transition in the duct work so
457mm
(18")
entire airflow is measured.
3 Adjust the "Supply Air Out" damper until
you reach the desired velocity. Follow
steps 1-3 to adjust the "Exhaust Air Out"
damper, if needed.