System Sensor Pipe Installation - Manual (Page 9)

User Guide: Aspirating Smoke Detector Pipe Installation
9
½ S ½ S ½ S
½ S ½ S ½ S
S
S
S S S
S
Regulatory Requirements
Local codes and regulations can determine the size and
spacing between the sample ports 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 FAAST systems.
Frequently Asked Question: How should the sample ports
be spaced?
Sample port spacing varies worldwide based on regulatory
standards. In the United States, sample ports shall be spaced
as defined per the requirements of NFPA. Each application
varies depending on the design. The requirements for sample
port square footage coverage is based on the detection
(Very Early Warning, Early Warning, or Standard) the design
is attempting to meet.
Transport times and obscuration levels required at each sample
port are as below:
Very Early Warning Fire Detection (VEWFD):
Sample port spacing: 200 sq. ft.
Transport time: 60 seconds from further port (includes test port)
Sample port sensitivity at pre-alarm: 0.2%obs/ft.
Sample port sensitivity at alarm: 1.0%obs/ft.
Early Warning Fire Detection (EWFD):
Sample port spacing: 400 sq. ft.
Transport time: 90 seconds from further port (includes test port)
Sample port sensitivity at alarm: 1.5%obs/ft.
Standard Fire Detection (SFD):
Sample port spacing: 900 sq. ft.
Transport time: 120 seconds from further port (includes test port)
Sample port sensitivity at alarm: 3.2%
Figure 9: Regulatory requirements.
This figure indicates the sample port spacing for each
classification requirement. The "S" indicates the maximum
distance allowed per sample port while "½ S" indicates
the maximum distance a sample port can be from a wall.
Each design will vary based on the shape of the building
but this template should be used as a starting point.
Design Classifications
Classification
Type
Area Per
Sample
Port
Maximum
Spacing
Between
Ports (S)
Maximum
Spacing
From Wall
(½ S)
VEWFD 200 sq. ft. 14 ft. 7 ft.
EWFD 400 sq. ft. 20 ft. 10 ft.
SFD 900 sq. ft. 30 ft. 15 ft.