323.0 Mechanical Equipment Schedules. [OSHPD 1,

1R, 2, 4 & 5] Mechanical equipment schedules in the con- struction documents shall clearly indicate which equipment will be powered by essential power or appropriate special seismic certifications.

2022 CALIFORNIA MECHANICAL CODE 57

GENERAL REGULATIONS

TABLE 303.10.1 REDUCTION OF CLEARANCES WITH SPECIFIED FORMS OF PROTECTION ^{1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11}

For SI units: 1 inch = 25.4 mm, °C = (°F-32)/1.8

Notes:

1 Reduction of clearances from combustible materials shall not interfere with combustion air, draft hood clearance and relief, and accessibility of servicing. 2 All clearances shall be measured from the outer surface of the combustible material to the nearest point on the surface of the appliance, disregarding any intervening protection applied to the combustible material. 3 Spacers and ties shall be of noncombustible material. No spacer or tie shall be used directly opposite the appliance or connector. 4 Where all clearance reduction systems use a ventilated air space, adequate provision for air circulation shall be provided as described. [See Figure 303.10.1(2) and Figure 303.10.1(3)] 5 At least 1 inch (25.4 mm) shall be between clearance reduction systems and combustible walls and ceilings for reduction systems using a ventilated air space. 6 Where a wall protector is mounted on a single flat wall away from corners, it shall have a minimum 1 inch (25.4 mm) air gap. To provide adequate air circulation, the bottom and top edges, or only the side and top edges, or all edges shall be left open. 7 Mineral wool batts (blanket or board) shall have a minimum density of 8 pounds per cubic foot (lb/ft3) (128 kg/m3) and a minimum melting point of 1500°F (816°C). 8 Insulation material used as part of a clearance reduction system shall have a thermal conductivity of 1 British thermal unit inch per hour square foot degree Fahrenheit [Btu•in/(h•ft ² •°F)] [0.1W/(m•K)] or less. 9 At least 1 inch (25.4 mm) shall be between the appliance and the protector. In no case shall the clearance between the appliance and the combustible surface be reduced below that allowed in Table 303.10.1. 10 All clearances and thicknesses are minimum; larger clearances and thicknesses are acceptable. 11 Listed single-wall connectors shall be installed in accordance with the manufacturer’s installation instructions.

58 2022 CALIFORNIA MECHANICAL CODE

GENERAL REGULATIONS

Notes: 1 A – Equals the clearance with no protection specified in Table 802.7.3.3 and Table 904.2.2 and in the sections applying to various types of equipment. 2 B – Equals the reduced clearance permitted in accordance with Table 303.10.1. 3 The protection applied to the construction using combustible material shall extend far enough in each direction to make C equal to A.

For SI units: 1 inch = 25.4 mm

FIGURE 303.10.1(3) MASONRY CLEARANCE REDUCTION SYSTEM

[NFPA 54: FIGURE 10.3.2.3(c)]

For SI units: 1 inch = 25.4 mm

Note: Masonry walls can be attached to combustible walls using wall ties. Spacers shall not be used directly behind appliance or connector.

FIGURE 303.10.1(2) WALL PROTECTOR CLEARANCE REDUCTION SYSTEM

[NFPA 54: FIGURE 10.3.2.3(b)]

2022 CALIFORNIA MECHANICAL CODE 59

FIGURE 303.10.1(1)1, 2, 3 EXTENT OF PROTECTION NECESSARY TO REDUCE CLEARANCES FROM GAS APPLIANCE OR VENT CONNECTORS

[NFPA 54: FIGURE 10.3.2.3(a)]

GENERAL REGULATIONS

For SI unit: 1 inch = 25.4 mm, 1 foot = 304.8 mm Notes:

first approved by the Authority Having Jurisdiction.

60 2022 CALIFORNIA MECHANICAL CODE

1 Support adjacent to joint, not to exceed 18 inches (457 mm). 2 Brace not to exceed 40 feet (12 192 mm) intervals to prevent horizontal movement. 3 Support at each horizontal branch connection. 4 Hangers shall not be placed on the coupling. 5 Vertical water lines shall be permitted to be supported in accordance with recognized engineering principles with regard to expansion and contraction, where

CALIFORNIA MECHANICAL CODE – MATRIX ADOPTION TABLE