System Sensor FAAST Comprehensive - Manual (Page 32)

Application and Design
ComprehenSive inSTruCTion mAnuAl
SCope
This section is intended to provide general design and application guidelines
for designing pipe networks in conjunction with the FAAST system. It contains
relevant design considerations and recommendations on how the FAAST sys-
tem may be installed in various applications.
DeSiGn
There are basic requirements that must be followed for a good site design. The
more information that is obtained up front, the easier the process will be. The
following items are provided to aid the design process.
• Understand local codes and standards.
• Gather all relevant information about the site, including the floor plan
for the protected space. The floor plan must also include existing or
proposed fixtures, fittings, air handlers, vents and other equipment that
requires special consideration.
• Determine the uses of the protected area to establish any special requirements.
• Verify the protection level required for the area, i.e. standard fire detec-
tion, early warning fire detection, very early warning fire detection.
• Use the PipeIQ® software to design the pipe network for the FAAST detector.
regulatory requirements
Local codes and regulations can determine the size and spacing between the
sample holes in a network, making them a critical part to any pipe design.
These requirements change depending on the type of environment being
monitored. Local codes and standards take precedence over any parameters
suggested by this document for the FAAST system.
Site layout And measurements
Planning of fire protection zones and relevant FAAST system locations are
needed to begin the planning process. The plan should include measurements
of the area to be protected and any areas designated for a different use. The
plan should also show any obstacles to the free flow of air in the space, i.e.
partitions or other large objects. Areas requiring special protection should also
be noted.
Locations of large machinery, equipment, cabinets or any other large items
that may affect the pipe network design also need to be indentified on the
plan. The pipe design can be overlaid onto an existing CAD drawing of the site
plan using the PipeIQ software.
Site Details
When designing the fire protection system, there are a number of site details
that need to be taken into account:
• Air flow and the location of air handling units, returns, exhaust systems, etc.
• Construction of areas being monitored – high ceilings, ceiling and floor voids
• Obstructions to the pipe layout – beams, walls, furniture
• Placement of equipment requiring any special protection – electrical
cabinets
• Monitoring requirements – on site, remote
• Activities within the environment – public space, office space, clean
room, warehouse, etc.
environmental Conditions
Identify as many ambient conditions that exist within the protected area of
the site. Typically different areas have different conditions. This includes in-
formation such as temperature, humidity and altitude. The more accurate the
information about the protected areas, the better the FAAST system can be
designed to meet those needs.
The environment, both internally and externally of the protected environment
(especially if air is being pulled in for heating or cooling), may have an ef-
fect on the operation of the FAAST detector. High pollution levels may cause
background levels of particulate matter in the protected area. The Acclimate
feature of the FAAST system helps to compensate for this background level.
This setting may be chosen during configuration. Or, if the environmental
changes are better defined by days of the week, the FAAST detector offers a
day/night/weekend mode.
In locations that are normally subjected to difficult environmental conditions,
such as loading docks or warehouse spaces, the FAAST detector is typically
located within a controlled environment, while the pipe network is located in
the harsh environment.
System Design
PipeIQ is designed to take the information gathered during this initial phase
and assist in designing the pipe network. There are two design methods
within the PipeIQ software. One offers a design wizard to create a simple
layout based on the parameters provided. The other allows for customization
throughout the process. Both methods provide the opportunity to go back
and modify the system as needed to accommodate the environment being
protected. For complete directions on the operation of PipeIQ refer to the sec-
tion titled PipeIQ.
SAmplinG meThoDS
There are two general types of sampling methods: standard pipe network
sampling and capillary tube sampling. From these sampling methods several
design configurations can be used to meet the needs of a particular site en-
vironment. Local codes and standards along with site requirements will help
determine the best air sampling method.
Standard pipe network Sampling
The following guidelines are used for any pipe network design. Also, some ad-
ditional guidelines specific to different sampling methods may apply.
1. Local codes and standards always take precedence over any values speci-
fied in this documentation.
2. Recommended pipe network material is nominal ¾ in. schedule 40 inter-
nal diameter (25 mm OD) CPVC, PVC, ABS or UPVC pipe.
3. There should be a minimum of 20 in. (500 mm) of straight pipe at the
FAAST detector input.
4. Sharp bends decrease airflow and performance.
5. All pipe designs must have an end cap.
6. Multiple shorter pipes provide better performance than a single longer
length pipe.
7. Symmetrical designs both in pipe length and hole size and distribution
are preferred to optimize FAAST system performance.
8. To prevent sampling holes from being blocked by dust and dirt, place the
holes on the bottom side of the sampling pipes, not on the top of the pipe.
This ensures that any falling debris does not clog the sampling holes.
9. To minimize the effect of pressure differentials, the sampled air should
be returned to the protected space wherever possible. This eliminates
any pressure differentials that might reduce the air flow in the pipe net-
work.
Capillary Tube Sampling
Capillary tube sampling is a method of locating sampling points remote from
the main sampling pipe. This is particularly useful where the main sampling
pipe cannot be routed through the area requiring protection for either techni-
cal or aesthetic reasons. Capillary tubes are also used to sample equipment
cabinets or enclosures within the protected area.
In the absence of any other guidance, it is recommended that a minimum
of two capillary sampling points are sited in a room. This allows a degree of
redundancy should any one hole become obstructed. PipeIQ will allow sam-
pling points and capillary tubes to be added as part of the design parameters.
Local codes and standards differ on issues, such as the minimum distance
detection points that can be positioned from walls and ceilings. It is important
that the specific local regulatory requirements are observed.
The following guidelines are recommended for capillary tube use.
1. Try to keep the length of capillaries the same.
2. Capillary tube length should not exceed 26 ft. (8 m).
3. When sampling equipment cabinets or other enclosures, the sampling point
is typically placed at or close to the top of the interior of the enclosure.
SS-400-007 33 E56-3621-003
Application and Design