- Electrical appliances. Electrical rating in volts, amperes and motor phase; identification of individual electrical components in volts, amperes or watts and motor phase; and in Btu/h (W) output and required clearances.
- Absorption units. Hourly rating in Btu/h (W), minimum hourly rating for units having step or automatic modulating controls, type of fuel, type of refrigerant, cooling capacity in Btu/h (W) and required clearances.
- Fuel-burning units. Hourly rating in Btu/h (W), type of fuel approved for use with the appliance and required clearances.
- Electric comfort-heating appliances. The electric rating in volts, amperes and phase; Btu/h (W) output rating; individual marking for each electrical component in amperes or watts, volts and phase; and required clearances from combustibles.
- Maintenance instructions. Required regular maintenance actions and title or publication number for the operation and maintenance manual for that particular model and type of product.
Exception: This section shall not apply to replacement appliances installed in existing compartments and alcoves where the working space clearances are in accordance with the equipment or appliance manufacturer's installation instructions.
- The passageway and level service space are not required where the appliance can be serviced and removed through the required opening.
- Where the passageway is unobstructed and not less than 6 feet (1829 mm) high and 22 inches (559 mm) wide for its entire length, the passageway shall be not more than 50 feet (15 250 mm) long.
- The passageway is not required where the level service space is present when the access is open, and the appliance can be serviced and removed through the required opening.
- Where the passageway is unobstructed and not less than 6 feet high (1929 mm) and 22 inches (559 mm) wide for its entire length, the passageway shall not be limited in length.
- Not less than 1-inch (25 mm) air space shall be provided between the protection and combustible wall surface.
- Air circulation shall be provided by having edges of the wall protection open at least 1 inch (25 mm).
- If the wall protection is mounted on a single flat wall away from corners, air circulation shall be provided by having the bottom and top edges, or the side and top edges open at least 1 inch (25 mm).
- Wall protection covering two walls in a corner shall be open at the bottom and top edges at least 1 inch (25 mm).
|TYPE OF PROTECTION APPLIED TO
AND COVERING ALL SURFACES OF
COMBUSTIBLE MATERIAL WITHIN THE
DISTANCE SPECIFIED AS THE
REQUIRED CLEARANCE WITH NO
PROTECTION (See Figures M1306.1 and
|WHERE THE REQUIRED CLEARANCE WITH NO PROTECTION FROM APPLIANCE,
VENT CONNECTOR, OR SINGLE WALL METAL PIPE IS:
|36 inches||18 inches||12 inches||9 inches||6 inches|
|Allowable clearances with specified protection (Inches)b|
|Use column 1 for clearances above an appliance or horizontal connector.
Use column 2 for clearances from an appliance, vertical connector and single-wall metal pipe.
|Above column 1||Sides and rear
|Sides and rear
|Sides and rear
|Sides and rear
|31/2-inch-thick masonry wall without ventilated air space||—||24||—||12||—||9||—||6||—||5|
|1/2-inch insulation board over 1-inch glass fiber or mineral wool batts||24||18||12||9||9||6||6||5||4||3|
|Galvanized sheet steel having a minimum thickness of 0.0236-inch (No. 24 gage) over 1-inch glass fiber or mineral wool batts reinforced with wire or rear face with a ventilated air space||18||12||9||6||6||4||5||3||3||3|
|31/2-inch-thick masonry wall with ventilated air space||—||12||—||6||—||6||—||6||—||6|
|Galvanized sheet steel having a minimum thickness of 0.0236-inch (No. 24 gage) with a ventilated air space 1-inch off the combustible assembly||18||12||9||6||6||4||5||3||3||2|
|1/2-inch-thick insulation board with ventilated air space||18||12||9||6||6||4||5||3||3||3|
|Galvanized sheet steel having a minimum thickness of 0.0236-inch (No. 24 gage) with ventilated air space over 24 gage sheet steel with a ventilated space||18||12||9||6||6||4||5||3||3||3|
|1-inch glass fiber or mineral wool
batts sandwiched between two
sheets of galvanized sheet steel
having a minimum thickness of 0.0236-inch (No. 24 gage) with a ventilated air space
- Reduction of clearances from combustible materials shall not interfere with combustion air, draft hood clearance and relief, and accessibility of servicing.
- Clearances shall be measured from the surface of the heat producing appliance or equipment to the outer surface of the combustible material or combustible assembly.
- Spacers and ties shall be of noncombustible material. No spacer or tie shall be used directly opposite appliance or connector.
- Where all clearance reduction systems use a ventilated air space, adequate provision for air circulation shall be provided as described. (See Figures M1306.1 and M1306.2.)
- There shall be at least 1 inch between clearance reduction systems and combustible walls and ceilings for reduction systems using ventilated air space.
- If a wall protector is mounted on a single flat wall away from corners, adequate air circulation shall be permitted to be provided by leaving only the bottom and top edges or only the side and top edges open with at least a 1-inch air gap.
- Mineral wool and glass fiber batts (blanket or board) shall have a minimum density of 8 pounds per cubic foot and a minimum melting point of 1,500°F.
- Insulation material used as part of a clearance reduction system shall have a thermal conductivity of 1.0 Btu inch per square foot per hour °F or less. Insulation board shall be formed of noncombustible material.
- There shall be at least 1 inch 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 this table.
- All clearances and thicknesses are minimum; larger clearances and thicknesses are acceptable.
- Listed single-wall connectors shall be permitted to be installed in accordance with the terms of their listing and the manufacturer's instructions.
- For limitations on clearance reduction for solid-fuel-burning appliances see Section M1306.2.1.