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Duct smoke housing, 2-wire
3
Mounting
3.1
Preparing the duct
Before installing the duct detector, you must verify the duct air flow and velocity. The detector
is designed for use in air handling systems with air velocities between 300 ft/min and 4000 ft/
min (1.5 m/s to 20.3 m/s). Check the HVAC engineering specifications to ensure the air
velocity in the duct falls within these parameters. If necessary, use a velocity meter to check
the air velocity in the duct.
3.2
Determining mounting location
To obtain a representative air sample, avoid stratification and dead air space. These
conditions can be caused by return duct openings, sharp turns, connections, or long,
uninterrupted runs. For this reason, place the duct housing in the range of six to ten times the
width of the duct from any uninterrupted run (see the following figure).
Figure 3.1: Typical duct detector placement
The D340 can be mounted in any direction of 90° increments without regard to the air flow
direction (see the following figure).
Bosch Security Systems, Inc.
1 Bend or other obstruction
3 Width of duct
2 6 to 10 times the width oft he duct
4 Return air inlet
Installation manual
Mounting | en
7
2017.04 | 7.0 | F.01U.071.685
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