What fire safety precautions must be taken in UFAD systems?
The combustibility of cabling (power, data, communication) contained in supply air plenums in underfloor air distribution systems is an important consideration. In general, applicable codes state that placing wires and cables in an air supply plenum is not a problem as long as they are contained in conduit, or are rated to be non-combustible. If not, the installation of sprinklers in the underfloor plenum may be required. Local fire codes often place restrictions on the size of open supply air plenums without any smoke breaks in the form of partitions separating the plenum into smaller zones. Typically, these fire codes limit the total area (e.g., less than 280 m2 [3,000 ft2]) and horizontal dimension in one direction (e.g., less than 9 m [30 ft]) of an unobstructed underfloor air supply plenum. During installation, it is important to ensure plenums are adequately sealed at junctions where a raised access floor meets a standard floor finish. Although advisable to avoid the use of sprin
