Planning For Forced Airflow - Bosch FCS‑320‑TM Series Operation Manual

Conventional Aspiration smoke detector
Distances of apertures
The distance between the T-piece and the following branch pipe as well as the pipe length
between aspiration apertures on the branch pipes must not exceed 12 m in total.
FAS / FCS
Maximum length of branch pipe
The length of pipe between the last T-piece and the last aspiration apertures is the length of
branch pipe. All other branch pipes need to be shorter. Two aspiration apertures in total can
be projected on each branch pipe.
If the maximum distance is exceeded a correction by an additional aspiration aperture on a
branch pipe can be done. In this connection please notice that two aspiration apertures in
total can be projected on each branch pipe.
Notice!
When the fire location (ROOM IDENT) localization must only be one aspiration aperture per
branch pipe can are projected. At least 3 m distance must be maintained between the suction
port of the first branch pipe and each configured subsequent aspiration aperture.
4.9

Planning for forced airflow

Monitoring the air-conditioning ducts
Air-conditioning units are broken down into low and high-speed units (see table below). The
details provided in this chapter apply only to low-speed units. There are no adequate empirical
values available for high-speed units. Hence, smoke trials must be executed for air-
conditioning ducts with flow speeds above 10 m/s, in order to determine optimal response
behavior.
Air-
conditioning
ducts
The speed distribution in an air-conditioning duct appears as follows:
Bosch Sicherheitssysteme GmbH
Low-speed units
Flow speed Maximum 6 to 10 m/s
Duct cross-section Large
Difference pressures Low
along the flow
direction
Operation guide
Planning | en 47
High-speed units
> 10 m/s
Small
High
2020.04 | 2.1 | F.01U.130.928