Planning
4
Measures against moisture condensation
50
Building Technologies
007016_i_en_--
Fire Safety
2012-09-07
Example:
DLR
DLR
FDL
1
2
3
Detection through one glass pane
1 Correct position
3 Glass pane
2 Incorrect position
Mounting reflectors on glass plates
When reflectors are installed on glass panes, there is danger of the glass panes,
not the reflector, reflecting the infrared ray. This may even occur after
commissioning, when the glass plate is slightly shifted. However, this is not the
case when the infrared ray does not hit the glass pane at a right angle, but at a
slight angle.
Recommendation: The infrared ray should reach the reflector at an angle of 5 to
10° to avoid unwanted reflection.
4.13
Measures against moisture condensation
Moisture condensation on the detector or reflector can cause faults and false
alarms. Moisture condensation can occur e.g. when the detector or reflector is
installed in a room with cool outer walls, where high air humidity and rapid
temperature increases can be expected as a result of sunshine on a non-insulated
roof, for example.
Use the detector heating unit DLH1191A for the linear smoke detector if there
is a danger of moisture condensation.
If there is a danger of moisture condensation, always use the reflector for long
distance and the built-in heating unit, even for short distances. You may not
use the reflectors for middle distance and short distance if there is a danger of
moisture condensation.
See also
