510.8 Underground Installations. Grease ducts installed

underground shall be approved for underground installation. The material of the grease duct shall be corrosion-resistant and shall comply with Section 510.5.1.

(1) Not less than 10 feet (3048 mm) of horizontal clear ance from the outlet to adjacent buildings, property lines, and air intakes. (2) Not less than 5 feet (1524 mm) of horizontal clear ance from the outlet (fan housing) to a combustible

(2) Not less than 5 feet (1524 mm) of horizontal clear ance from the outlet (fan housing) to a combustible structure. (3) A vertical separation of 3 feet (914 mm) below an

exhaust outlet for air intakes within 10 feet (3048

(3) A vertical separation of 3 feet (914 mm) below an

exhaust outlet for air intakes within 10 feet (3048 mm) of the exhaust outlet. (4) The ability to drain grease out of traps or low points

formed in the fan or duct near the termination of the

(4) The ability to drain grease out of traps or low points

formed in the fan or duct near the termination of the system into a collection container that is noncombustible, closed, rainproof, and structurally sound for the service to which it is applied, and that will not sustain combustion. (5) A grease collection device that is applied to exhaust

systems that does not inhibit the performance of a

(5) A grease collection device that is applied to exhaust

systems that does not inhibit the performance of a fan. (6) A listed grease collection system that is in accor dance with Section 510.9.1(4) and Section

(6) A listed grease collection system that is in accor dance with Section 510.9.1(4) and Section 510.9.1(5). (7) A listed grease duct in accordance with Section

507.4.7 or ductwork in accordance with Section

(7) A listed grease duct in accordance with Section

507.4.7 or ductwork in accordance with Section 507.4.8. (8) A hinged upblast fan supplied with flexible weath erproof electrical cable and service hold-open

A hinged upblast fan supplied with flexible weath erproof electrical cable and service hold-open retainer to permit inspection and cleaning that is listed for commercial cooking equipment with the following conditions: (a) Where the fan attaches to the ductwork, the duct work is not less than 18 inches (457 mm) away

(a) Where the fan attaches to the ductwork, the duct work is not less than 18 inches (457 mm) away from the roof surface, as shown in Figure 510.9.1. (b) The fan discharges not less than 40 inches

(1016 mm) away from the roof surface, as

(b) The fan discharges not less than 40 inches

(1016 mm) away from the roof surface, as shown in Figure 510.9.1. (9) Other approved fan, provided it is in accordance

with the following criteria:

510.8.1 Grease Receptacle. The grease duct shall be sloped to drain the grease back to an approved grease collection device. A grease collection device shall be located at the base of the vertical riser. 510.8.2 Cleanouts. For horizontal installations, cleanouts for cleaning and maintenance shall be provided on the top portion of the grease duct in accordance with Section 510.3 and shall be labeled at the interior portion of the duct. The exhaust system shall terminate as follows: 510.9 Termination of Type I Hood Exhaust System. (1) Outside the building with a fan or duct.

Other approved fan, provided it is in accordance

with the following criteria: (a) The fan is in accordance with the requirements

of Section 510.9.1(3) and Section 511.1.3.

(a) The fan is in accordance with the requirements

of Section 510.9.1(3) and Section 511.1.3. (b) Its discharge or its extended duct discharge is

in accordance with the requirements of Section

(b) Its discharge or its extended duct discharge is

in accordance with the requirements of Section 510.9.1(2). (See Section 511.1.3) (c) Exhaust fan discharge is directed up and away

from the roof surface. [NFPA 96:7.8.2.1]

from the roof surface. [NFPA 96:7.8.2.1] 510.9.1.1 Listed Flexible Connectors. Listed flexible connectors shall be permitted to be used on exterior roof locations where required for proper equipment vibration isolation. 510.9.1.2 Inspection and Cleaning. Fans shall be provided with safe access and a work surface for inspection and cleaning. [NFPA 96:7.8.2.2]

104 2019 CALIFORNIA MECHANICAL CODE

EXHAUST SYSTEM

FIGURE 510.9.1 UPBLAST FAN CLEARANCES

[NFPA 96: FIGURE 7.8.2.1]

510.9.2 Wall Terminations. Wall terminations shall be arranged with or provided with the following properties: (1) Through a noncombustible wall with not less than

10 feet (3048 mm) of clearance from the outlet to

(1) Through a noncombustible wall with not less than

10 feet (3048 mm) of clearance from the outlet to adjacent buildings, property lines, grade level, combustible construction, electrical equipment or lines, and the closest point of an air intake or operable door or window at or below the plane of the exhaust termination. The closest point of an air intake or operable door or window above the plane of the exhaust termination shall be not less than 10 feet (3048 mm) in distance, plus 3 inches (76 mm) for each 1 degree (0.017 rad) from horizontal, the angle of degree being measured from the center of the exhaust termination to the center of the air intake, operable door or window, as indicated in Figure 510.9.2. Exception: A wall termination in a secured area shall be permitted to be at a lower height above grade where acceptable to the Authority Having Jurisdiction. (2) The exhaust flow shall be directed perpendicularly

outward from the wall face or upward.

(2) The exhaust flow shall be directed perpendicularly

outward from the wall face or upward. (3) The ductwork shall be pitched to drain the grease

back into the hood(s) or with a drain provided to

(3) The ductwork shall be pitched to drain the grease

back into the hood(s) or with a drain provided to bring the grease back into a container within the building or into a remote grease trap. (4) A listed grease duct shall comply with Section

510.3.3 through Section 510.3.7; other ducts shall

Notes:

Fresh air intake (FAI) applies to an air intake, including an operable door or window.
Example: FAI is same plane as exhaust or lower: 10 feet (min.) between closest edges. FAI above plane of exhaust: 10 feet + 3 inches.

FIGURE 510.9.2 EXHAUST TERMINATION DISTANCE FROM FRESH AIR INTAKE

(FAI) OR OPERABLE DOOR OR WINDOW

[NFPA 96: FIGURE 7.8.3]