Bosch FAS-420-TP2 - Page 69

Aspiration smoke detector LSN improved Planning | en 69
Bosch Sicherheitssysteme GmbH Operation guide 2020.04 | 6.1 | F.01U.029.275
1
1
5
2
2
i
1 2 3 4 5 6 7 8 9 10
4
3
3
F
v
1
v
2
v
3
v
4
A
FAS / FCS
FAS / FCS
5
1/2 b
b
2
FAS-420
-
TM
se
ries
A
B
Air-return pipe
F Front view
A Plan view
1 Air-conditioning duct
2 Duct adapter
3 Airflow
4 Aspiration
5 Air-return pipe
b Width of air-conditioning
duct
v
1
-v
4
Flow speed
Air-return pipe
The air-return pipe must be positioned at a distance of at least 2m from the aspiration. The
open end of the return is sloped at a 45° angle.
1
i
1 2 3 4 5 6 7 8 9 10
v
1
v
2
v
3
v
4
FAS / FCS
2
2
≥ 200 mm
3
A
B
Offset arrangement of the air return
1 Air-conditioning duct
2 Duct adapter
3 Airflow
A Aspiration in area v1
B Return in area v3
v1 to
v4
Flow speed
If the distance of 2m cannot be adhered to, the pipes must be arranged offset. This way, a
pressure fall between intake and exhaust can be achieved since the pipes are located in
different speed ranges.
The distance of the air sampling openings to one another and to the duct wall is represented
in the following table.
Bore distances Duct cross-
section ≤0.5m²
Duct cross-
section >0.5m²
Distance of the air sampling openings
to the wall
100 to 200mm 200 to 300mm
Distance of the air sampling openings
to one another
100mm 150mm