MAN3186 - TITANUS MICRO
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SENS®
99
5.3.4 Project planning with forced air flow
Air conditioning duct
monitoring
Air conditioning systems are distinguished between low-speed and high-
speed systems.
The information listed in this section only applies to low-speed systems.
There are insufficient empirical values for high-speed systems. For that
reason, smoke tests are to be conducted with air conditioning ducts having
flow rates higher than 10 m/s to determine the optimum response
characteristics.
Low-speed systems
High-speed systems
Flow speed [m/s]
Max. 6
… 10
> 10
Duct cross-section
High
Low
Pressure differential along the
direction of flow
Low
High
Table 43:
Differences between low-speed and high-speed systems
The rate distribution in an air conditioning duct looks like this:
Image 61:
Speed distribution in the air-conditioning duct
1
Cross-section of air-conditioning duct
2
Areas V1 … V4
3
Centre of the air-conditioning duct (highest air flow)
4
Outer area of the air-conditioning duct (lowest air flow)
Aspiration
The pipe system must be arranged in area V
1
to V
3
to achieve optimum
detection results.
V
4
V
3
V
2
V
1
1
2
3
4
