Smoke Alarm User Manual

Installation, Operation and Maintenance Manual
Page 2-2 Issue 1
February 2001
In addition to the detector, a sampling pipe network is required to carry the sampled air from the protected
area to the detector. Overall performance of the High Sensitivity Smoke Detection system is dependent
upon the layout of the air sampling pipe network. Use of the “SNIFF” computerised program balances the
piping network to provide for an equal intake of air at each sampling hole. For a detailed description on
how to design a pipe network reference should be made to the SNIFF Manual (Version 3.0).
The sampling pipe network is normally constructed from ½ inch, ¾ inch, or 1-inch internal-diameter
smooth bore pipe. The type of pipe is not critical because of the low operating pressures. Any smooth
bore pipe will be satisfactory provided it is rigid enough so that it does not sag between supports and it
meets all code requirements. Some commonly used types are PVC, ABS, CPVC, EMT and copper
tubing. Flexible tubing can be used for sampling hole drops.