Pipe Design
TITANUS
SUPER·SENS
®
4 –
38
Data: 02/09
TSS_04_A-en-e
4.3.4.2
Detection of air conditioning ducts
Air conditioning duct
monitoring
Air conditioners are distinguished between low-speed and high-speed
systems (see table below). The specifications provided in this chapter
apply
only to low-speed systems
. There are not enough empirical val-
ues available for high-speed systems. For that reason, smoke tests
should be conducted with air conditioning ducts having flow rates higher
than 10 m/s and the optimum response characteristics should be deter-
mined.
Low-speed systems
High-speed systems
Flow rate
10 m/s maximum
> 10 m/s
Duct cross section
Large
Small
Pressure differential
along the direction of
flow
Low High
The rate distribution in an air conditioning duct looks like this:
Fig. 4.21: Rate distribution in an air conditioning duct with v
1
> v
2
> v
3
> v
4
Sampling
The pipe system should be arranged in area v
1
to v
3
in order to achieve
optimum detection results.
Installation
location
of the pipe system
The air exhaust duct should be chosen as the installation location of the
pipe system and should be as far away from sound suppressors, air baf-
fles and bends as possible. The benchmark for the distance from such
‘obstacles’ is: At least 3x the smallest duct diameter.