VESDA Pipe Network Design Guide
VESDA by Xtralis
12
www.xtralis.com
4.4
Return Area Protection
4.4.1
In-ceiling or Floor Void Sampling
Some applications use ceiling and under floor voids as return air plenums (ducts). The pipe network is
designed to monitor the air flowing through the return air plenums. In-ceiling or floor void sampling is also used
to monitor any cabling and equipment that may be installed in the ceiling and floor voids. In instances where
the airflow is perpendicular to the pipe then it is recommended that sampling holes have a 30° orientation to
the airflow. Refer to Figure 4-12 on page 15.
Legend
A
Ceiling Void
B
Sampling Holes
Figure 4-5: Ceiling void sampling
Legend
A
Floor Void
B
Sampling Holes
Figure 4-6: Floor Void Sampling
4.4.2
Return Air Sampling
Smoke tends to travel with any mechanically generated air flow. Correctly positioning sampling holes in a pipe
network across the return air grille of an Air Handling Unit (AHU) or an exhaust ventilation system, ensures
that any smoke is detected at the earliest stage. Air samples from inside a duct carrying the exhaust air may
also be collected, refer to Figure 4-8 for details. It is recommended that the sampling holes face between 20
and 45 degrees from the direction of the greatest airflow. Refer to Figure 4-7 for further information.
Figure 4-7: Cross section of pipe position on a return air grille
Summary of Contents for VESDA VLC-505
Page 1: ...VESDA Student Workbook Rev 8a 15SEP21 ...
Page 4: ...iv ...
Page 14: ...VESDA Course Overview 1 10 VESDA Student Workbook Create Xtralis Account ...
Page 20: ...VESDA Course Overview 1 16 VESDA Student Workbook ...
Page 23: ...VESDA Products VESDA Student Workbook 2 3 ASD iVESDA ASD ...
Page 24: ...VESDA Products 2 4 VESDA Student Workbook VESDA model comparison chart ...
Page 32: ...VESDA Products 2 12 VESDA Student Workbook Industrial facilities Industrial facilities ...
Page 33: ...VESDA Products VESDA Student Workbook 2 13 Solutions for all environments Detectors ...
Page 56: ...Installation 3 4 VESDA Student Workbook IDP Installation Practices ...
Page 68: ...Installation 3 16 VESDA Student Workbook ...
Page 74: ...VESDAnet Connection 4 6 VESDA Student Workbook ...
Page 218: ...VSC Software Installation A 4 VESDA Student Workbook ...
Page 224: ...ASPIRE Software Installation B 6 VESDA Student Workbook ...
Page 238: ...14 ...
Page 239: ...VESDA Pipe Network Design Guide February 2019 Document 10193_09 Part Number 30009 ...
Page 240: ......
Page 293: ...VESDA Pipe Network Installation Guide March 2019 Document 10255_08 Part Number 30008 ...
Page 294: ......
Page 333: ......
Page 334: ...VESDA Commissioning Guide December 2012 Document 10195_06 Part Number 30005 ...
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