System Sensor Pipe Installation - Manual (Page 13)

User Guide: Aspirating Smoke Detector Pipe Installation
13
Inter-Beam / Below-Beam Sampling
When large ceiling beams are used in construction, pockets of
space are created between the beams. In normal circumstanc-
es, the pipe network is mounted on the bottom of the beams
and does not sample the large space between the beams. If it
is necessary to cover this space, a rigid pipe in the shape of an
inverted “L” can be extended vertically from the pipe network
up into the area between the beams so that the pipe reaches up
towards the ceiling in these locations. The sampling port should
be drilled just before the end cap on the horizontal portion of the
pipe. The ends of these sampling pipes should be capped with
an end cap, which may or may not have a sample port based
on the pipe network design.
Frequently Asked Question – How do I know if the beam
pocket has to be protected?
In exposed beam construction the sample port shall be spaced
based on the requirements of NFPA 72®. If the beam depth is
equal to or greater than 10% of the ceiling height and beam
spacing is greater than or equal to 40% of the ceiling height,
than detection shall be provided in each beam pocket per NFPA
72®. For beams with less than 10% of ceiling height, smooth
ceiling spacing shall be permitted.
Under Floor Protection
Floor Void Sampling
The FAAST system is well suited to protect concealed voids,
either in the ceiling or under the floor. Some locations use either
ceiling and/or under floor voids as return air plenums (ducts).
A pipe network must be designed to monitor the flow of return
air through these areas. Some ceiling and floor voids are used
for cable runs or for small equipment installation. Monitoring of
these areas must be done using a pipe network designed for
operation in these areas. When installing pipe in a floor void,
keep in mind that the air sampling ports are still located at
the bottom of the pipe. This means the pipe would be located
towards the upper portion of the void.
Frequently Asked Question – Can I monitor the ceiling and
under the floor with one detector?
FAAST can monitor two areas with one detector, however,
it is not recommended practice due to pressure differentials.
Areas with pressure difference of +/- 20% delta of one another
can create air flow faults. Therefore it is recommended to
provide each area with its own detector.
Floor Void Test Sample Port
It is recommended to install a test sample port when designing
an under floor system. A test sample port will allow an easier
commissioning process without disrupting the floor operation.
It is recommended to locate the test port at the end of each
branch pipe at a minimum of 18 in. above the raised floor. The
port diameter should be determined and verified by using the
PipeIQ Software.
Sampling Pipe
Sampling Port
End cap
Beam Pocket
+40% (0.4H)
+10% (0.1H)
Figure 14: Inter-beam sampling.
Figure 15: Below-beam sampling.
Figure 16: Floor void sampling.
Figure 17: Floor void test sample port location.
Sampling Pipe
Floor
Ground
Floor Supports
Floor Void Sampling Port
Sampling Pipe
Floor
Sampling Port
18 in.
(450 mm)
End cap with
Sample Test Port
Sampling Pipe Sampling Port
MAX SPACING MAX SPACING
N/A
-10% (0.1H)