Bosch FAS-420-TT Series - Project Planning with Branch Pipes

70 en | Planning Aspiration smoke detector LSN improved
2020.04 | 6.1 | F.01U.029.275 Operation guide Bosch Sicherheitssysteme GmbH
Diameter of the air sampling openings
The diameter of the air sampling openings is derived from the number of air sampling
openings. The precise value can be obtained from Simplified pipe planning.
The pipe is closed with an end cap without bore hole.
Arrangement
The air sampling openings must face the airflow.
Note when planning that the air-conditioning ducts are often only accessible from two sides
for installation of the pipe system.
Example
The figure below shows two planning examples of pipe systems in air-conditioning ducts.
FAS / FCSFAS / FCS
A ≤ 0,5 m
2
A > 0,5 m
2
a
100
100
200
150
b
1/2 b
b
1/2 b
a
Ducts with small and large duct cross-sections
A Cross-sectional area of
duct (with A=axb)
a Height of air-conditioning
duct
b Width of air-conditioning
duct
Refer to
– Simplified pipe planning, page 53
4.12 Project planning with branch pipes
Project planning with branch pipe are suitable for sampling points which are located distantly
from the main run of the pipe system.