509.8 Through-the-Wall Vent Termination.

A mechanical draft venting system shall terminate at least 3 feet (914 mm) above any forced air inlet located within 10 feet (3048 mm) (See Figure 509.8). Exceptions: (1) This provision shall not apply to the combustion air

intake of a direct-vent appliance. (2) This provision shall not apply to the separation of the

(2) Where a single-wall metal pipe is used and has a shape

other than round, it shall have an equivalent effective area equal to the effective area of the round pipe for which it is substituted and the minimum internal dimension of the pipe shall be 2 inches (50 mm). (3) The vent cap or a roof assembly shall have a venting

feet (1219 mm) horizontally from, or 1 foot (305 mm) above any door, operable window, or gravity air inlet into any building. The bottom of the vent terminal shall be located at least 12 inches (305 mm) above finished ground level. [NFPA 54:12.9.2] 509.8.2 Direct-Vent Appliance. The clearances for through-the-wall direct-vent terminals shall be in accordance with Table 509.8.2. The bottom of the vent terminal and the air intake shall be located not less than 12 inches (305 mm) above finished ground level. [NFPA 54:12.9.3]

TABLE 509.8.2 THROUGH-THE-WALL DIRECT-VENT TERMINATION

CLEARANCES

[NFPA 54: TABLE 12.9.3]

integral outdoor air inlet and flue gas discharge of listed outdoor appliances. [NFPA 54:12.9.1] 509.8.1 Mechanical Draft Venting System. A mechanical draft venting system of other than direct-vent type shall terminate at least 4 feet (1219 mm) below, 4

For SI Units: 1 inch = 25.4 mm, 1000 British thermal units per hour = 0.293 kW

EXIT TERMINALS OF MECHANICAL DRAFT AND DIRECT-VENT VENTING SYSTEMS

[NFPA 54: FIGURE A.12.9]

100 2022 CALIFORNIA PLUMBING CODE

509.8.3 Category I through Category IV and Non- categorized Appliances. Through-the-wall vents for Category II and Category IV appliances and noncategorized condensing appliances shall not terminate over public walkways or over an area where condensate or vapor could create a nuisance or hazard or could be detrimental to the operation of regulators, relief valves, or other equipment. Where local experience indicates that condensate is a problem with Category I and Category III appliances, this provision shall also apply.

appliances and noncategorized condensing appliances shall not terminate over public walkways or over an area where condensate or vapor could create a nuisance or hazard or could be detrimental to the operation of regulators, relief valves, or other equipment. Where local experience indicates that condensate is a problem with Category I and Category III appliances, this provision shall also apply.

Drains for condensate shall be installed in accordance with the appliance and the vent manufacturer’s installation instructions. [NFPA 54:12.9.4] 509.8.4 Annular Spaces. Where vents, including those for direct-vent appliances or combustion air intake pipes, penetrate outside walls of buildings, the annular spaces around such penetrations shall be permanently sealed using approved materials to prevent entry of combustion products into the building. [NFPA 54:12.9.5] 509.8.5 Vent Terminals. Vent systems for Category IV appliances that terminate through an outside wall of a building and discharge flue gases perpendicular to the adjacent wall shall be located not less than 10 feet (3048 mm) horizontally from an operable opening in an adjacent building. Exception: This shall not apply to vent terminals that are 2 feet (610 mm) or more above or 25 feet (7620 mm) or more below operable openings. [NFPA 54:12.9.6]