(a)  Unobstructed air openings shall be sized on the basis of 1 sq. in. (650 sq. mm) free area per 2000 Btu/hr. maximum fuel input of the combined burners located in the boiler room, or as specified in the National Fire Protection Association (NFPA) standards for oil and gas burning installations for the particular job conditions. The boiler room air supply openings shall be kept clear at all times.

(b)  Power ventilators or fans shall be sized on the basis of 0.2 cfm (0.0057 cubic meters per minute) for each 1000 Btu/hr. of maximum fuel input for the combined burners of all boilers and water heaters located in the boiler room.

(c)  When power ventilators or fans are used to supply combustion air they shall be installed with interlock devices so that the burners will not operate without an adequate number of ventilators/fans in operation.

(d)  Oil, gas and solid fuel fired boilers and pressure vessels shall be equipped with exhaust flues, stacks, or chimneys discharging to a safe point outside of the building.


History Note:        Authority G.S. 95‑69.11; 95‑69.14;

Eff. May 29, 1981;

Amended Eff. January 1, 1982;

Recodified from 13 NCAC 13 .0413 Eff. January 1, 1995;

Amended Eff. July 1, 2006; January 1, 1995;

Pursuant to G.S. 150B-21.3A, rule is necessary without substantive public interest Eff. July 22, 2018.