Pitot
tube
Pitot tube
Magnehelic
gauge
(option #1)
Min 3 ft straight duct
#2
#3
Remove plug
while balancing
Min 3 ft straight duct
#1
#4
Air Flow Balancing (cont’d)
5"
6"
DUCTDIAM. CROSSSECTIONAREA
The accuracy of the flow reading will be affected by how close to any elbows or bends the readings are taken.
Accuracy can be increased by taking an average of multiple readings as outlined in the literature with the Pitot tube.
Note: To take more accurate readings, use option #1(if possible).
Note:(Option #2)
*For this option, please use field balancing
ports.
*Do not use pitot tube to open holes in the
insulation as it may block/damage the pitot tube.
*Take 3 readings on each hole and average
all 3 readings for supply and same for exhaust.
*After finish balancing, plug both holes with
plastic plugs provided with the unit.
CFM = Opening / Cross-sectional Area(sq.ft.) x velocity(FPM)
8
Maintenance
Regular Maintenance
1. Turn the unit off and disconnect the power supply.
2. Unlatch the door and lift the door panel towards you, hold it firmly and slide it to the left.
3. Clean the inside of the door and drain pan with a damp cloth to remove dirt and debris
that may be present.
4. Clean the filters: (twice a year)
- Remove the filters.
- Vacuum to remove most of the dust.
- Wash with a mixture of warm water and mild soap. Rinse thoroughly and shakefilters
to remove water and let dry.
5. Oil/grease defrost damper levers and hinges.
6. . Check air flow sensors twice a year for lint/dust accumulation. If necessary, clean the sensors
with a lintfree cloth. Take extra care while handling. make sure supply sensor goes back to
supply diffuser and exhaust sensor goes back to exhaust diffuser on same original position.
7. Check the exterior fresh air supply hood:
- Make sure there are no leaves, twigs, grass, ice or snow that could be drawn into the vent.
Partial blocking of this air vent could cause the unit to malfunction.
8. Reassemble the components, Filters and Door (The door is secured when you hear a click.)
9. Reconnect the power and turn on the unit.
P"
CFM
Ø5” Ø6”
0.010 0.004 50
0.012 0.006 60
0.016 0.008 70
0.022 0.010 80
0.027 0.013 90
0.034 0.016 100
0.041 0.020 110
0.048 0.023 120
0.057 0.027 130
0.136sq.ft.
0.196sq.ft.
P
"
= Velocity Pressure in inch
Remove plug
while balancing
(Option #2)