Installation Sheet

Braeburn Systems LLC , 2 215 Cornell A venue, Mo ntgomery, Illinois 60 5 38, U.S.A.
Teleph o ne (866) 268 -5599, Fa c simile ( 8 66) 268- 361 1
Barometric Bypass Damper Set-up Instructions
Bypass Damper adjustment is critical in order for any zone system to work properly. When the
damper is removed for the box, the weighted arm will be attached to the shaft. It must be adjusted
to the 4 o'clock position on the side with the airflow label. If the damper arm is moved to the oppo-
site side of the damper from the airflow label, the damper arm must be placed in the 8 o'clock posi-
tion.
This is the way the Bypass Damper is usually set up with the damper arm and arrow label on the
same side. Adjust the damper arm to the 4 o'clock position with the damper closed.
Sometimes it is easier to access the damper arm by moving it to the opposite side of the Bypass
Damper. If the damper arm is moved to the opposite side (side without arrow label), adjust the
damper arm to the 8 o'clock position with the damper closed.
Adjust the damper arm to the 4 o’clock position with the damper closed.
First. remove the damper arm from the bypass damper. For proper adjustment, place a weight on
the short side of the blade near the shaft. Move the weight just enough toward the outside until
the blade stays in the closed position and fasten the weight to the damper bladed with a sheet
metal screw or bolt. Re-attach the damper arm and adjust the damper arm to the 4 o’clock
position with the damper closed.
1. Make a call for heating or cooling in every zone. Verify that all zone dampers open.
2. Verify that the Barometric Bypass Damper is fully closed with the damper arm in the 4 or
8 o’ clock position. Sometimes. a duct system will have higher than normal static pres
sure and an additional weight may be required to keep the bypass damper closed with all
zones open. Slowly move the weight toward the shaft in ½ inch increments until the
bypass damper starts to open slightly. Then move the weight in the opposite direction
about a ½ inch or until the damper just barely stays closed.
3. Close one or more zones and the Barometric Bypass Damper should open. Do not worry
about how far the Bypass Damper opens as it will self-adjust.
Size the Barometric Bypass Damper for the maximum amount of bypass airflow through the
bypass. Subtract the smallest zone CFM from the total CFM to determine bypass CFM. Select
the bypass damper from the chart below:
Horizontal AIRFLOW - Left to Right
Horizontal AIRFLOW - Right to Left
Vertical AIRFLOW - UP
Vertical AIRFLOW - DOWN
Bypass Damper Size CFM
10” 800
12” 1200
14” 1600
16” 2000