VESDA
®
LaserFOCUS VLF-500 Product Guide
19
The set up below shows a branched pipe arrangement with 5 sampling holes per branch and
fitted end caps without sampling holes.
Figure 19 - Open hole, branched pipe
The set up below shows a branched pipe arrangement with 3 capillary drop pipes per branch and
fitted end caps without sampling holes.
Figure 20 - Capillary pipes, branched pipe
Return air sampling (return grilles)
The VESDA LaserFOCUS is suitable for air sampling across return air grilles of Air Handling
Units. The recommended coverage of the VESDA LaserFOCUS is 0.4 m
2
(4 sq. ft.) per sampling
hole. This should be considered in conjunction with local codes and standard.
Note:
Rotate the air sampling hole approximately 45
o
away from the direction of the
incoming airflow and towards the grille surface. This will minimize the risk of a
Low Flow Fault being recorded in situations where air flow changes
(e.g. where the Air Handling Unit is turned off).
C
B
C
A
Legend
A
Smoke detector
B
Sampling hole
C
End cap (no hole)
A
B
C
B
C
Legend
A
Smoke detector
B
Capillary tube
C
End cap (no hole)
