503.2.7.1.3 High-Pressure Duct Systems
Ducts designed to operate at static pressures in excess of 3 inches w.g. (746 Pa) shall be insulated and sealed in accordance with Section 503.2.7. In addition, ducts and plenums shall be leak-tested in accordance with the SMACNA HVAC Air Duct Leakage Test Manual with the rate of air leakage (CL) less than or equal to 6.0 as determined in accordance with Equation 5-2.
CL = F × P 0.65 (Equation 5-2)
F = The measured leakage rate in cfm per 100 square feet of duct surface.
P = The static pressure of the test.
Documentation shall be furnished by the designer demonstrating that representative sections totaling at least 25 percent of the duct area have been tested and that all tested sections meet the requirements of this section.