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5.4 Setting the Damper Positions
To ensure equal draft to all fireplaces, each damper must be individually preset to an OPEN position.
Because the fireplaces that are closer to the fan see more airflow than those farther away, the
closer fireplaces do not need to be open to the full 90° to maintain the pressure set point in the connector.
However, during operation, you should assume that the dampers farthest from the fireplace
will be fully open to 90°.
To set the damper positions:
1. Begin with the fireplace closest to the fan.
2. All dampers should be closed except for the one being set.
3. Set the damper to 45
o
. To test the appropriate damper position:
a. Place a smoke match or a piece of thin paper above the fireplace opening.
b. If the fireplace is pulling too much, close off the damper and retest.
c. If the fireplace is spilling, adjust the damper to >45° and retest.
d. Repeat until the proper flow is maintained.
4. Working from the top floor to the bottom floor, repeat the above procedure for all fireplaces.
