Air Products and Controls Combats Commonly Overlooked Code Violation
Educational program focuses on air sampling tube lengths in duct smoke detectors
Pontiac, Michigan (December 18, 2007)- To reduce the incidence of a commonly overlooked code violation and ensure the safety of end users of their products, Air Products and Controls (APC) has launched an educational campaign to raise awareness of code-driven requirements for air sampling tube length in duct smoke detectors.
IMC (Chapter 606.3) and NFPA 72 (Chapter 220.127.116.11) codes require that all smoke detector installations, tests and inspections are made in accordance with the manufacturer’s published instructions. In most cases, manufacturer specs call for the air sampling tube to extend between 2/3 and 80% of the duct width. If the sample tube does not span the width of the duct, smoke can bypass the sample tube and avoid immediate detection, allowing the fire to progress and placing all those who rely on the smoke detection system in danger. In addition to this potential liability, improperly sized sampling tubes can result in failed inspections, increased job costs and jeopardized inspector relationships.
Some manufacturers supply sample tubes with duct smoke detector purchases. However, the standard sample tube supplied is approximately 12 inches in length, meaning it is only code-compliant in ducts up to 18 inches wide. Particularly in commercial applications, where duct widths are more commonly 36 inches wide, the supplied sample tube would not meet code. Building inspectors are reporting an increase of non-compliant tube spans.
APC’s campaign reminds customers that one size does not fit all, and urges them to take application duct size into account when determining if the standard air sampling tube length is sufficient. All manufacturers that supply air duct smoke detectors offer air sampling tubes that will accommodate duct widths of up to ten feet. Tubes can always be cut down to size, and in some cases, two metal tubes may be spliced together to meet distance requirements.
For more information on correct air sampling tube sizing, download APC’s free “Size Does Matter” informational pamphlet here or contact APC at 888-332-2241.