Exception: The appliance, equipment and system installations regulated by this code are permitted to be located below the design flood elevation provided that they are designed and installed to prevent water from entering or accumulating within the components and to resist hydrostatic and hydrodynamic loads and stresses, including the effects of buoyancy, during the occurrence of flooding to the design flood elevation and shall comply with the flood-resistant construction requirements of the Building Code of New York State.
Exception: Where the penetrating items are steel, ferrous or copper pipes, tubes or conduits, the annular space between the penetrating item and the fire-resistance-rated wall is permitted to be protected as follows:
Exception: Floor penetrations contained and located within the cavity of a wall do not require a T rating.
Exception: Type 1 clothes dryers that are provided with makeup air in accordance with Section 614.5.
For appliances other than fan-assisted, calculate volume using Equation 3-1.
| ||(Equation 3-1)|
For fan-assisted appliances, calculate volume using Equation 3-2.
| ||Equation 3-2)|
Iother = All appliances other than fan assisted (input in Btu/h).
Ifan = Fan-assisted appliance (input in Btu/h).
ACH = Air change per hour (percent of volume of space exchanged per hour, expressed as a decimal).
For purposes of this calculation, an infiltration rate greater than 0.60 ACH shall not be used in Equations 3-1 and 3-2.
Where directly communicating with the outdoors, or where communicating with the outdoors through vertical ducts, each opening shall have a minimum free area of 1 square inch per 4,000 Btu/h (550 mm 2 /kW) of total input rating of all appliances in the enclosure [see Figures 304.6.1(1) and 304.6.1(2)].
Where communicating with the outdoors through horizontal ducts, each opening shall have a minimum free area of not less than 1 square inch per 2,000 Btu/h (1100 mm 2 /kW) of total input rating of all appliances in the enclosure [see Figure 304.6.1(3)].
FIGURE 304.6.1(1)ALL AIR FROM OUTDOORS-INLET AIR FROM VENTILATED CRAWL SPACE AND OUTLET AIR TO VENTILATED ATTIC(see Section 304.6.1)
FIGURE 304.6.1(2)ALL AIR FROM OUTDOORS THROUGH VENTILATED ATTIC(see Section 304.6.1)
FIGURE 304.6.1(3) ALL AIR FROM OUTDOORS (see Section 304.6.1)
FIGURE 304.6.2 SINGLE COMBUSTION AIR OPENING, ALL AIR FROM THE OUTDOORS (see Section 304.6.2)
Exception: Within dwelling units, unobstructed stud and joist spaces shall not be prohibited from conveying combustion air, provided that not more than one required fireblock is removed.
Exception: Direct-vent gas-fired appliances designed for installation in a solid fuel-burning fireplace where installed in accordance with the manufacturer’s instructions.
In barbershops, beauty shops and other facilities where chemicals that generate corrosive or flammable products, such as aerosol sprays, are routinely used, nondirect vent-type appliances shall be located in a mechanical room separated or partitioned off from other areas with provisions for combustion air and dilution air from the outdoors. Direct-vent appliances shall be installed in accordance with the appliance manufacturer’s installation instructions.
Unlisted appliances approved in accordance with Section 301.3 shall be limited to uses recommended by the manufacturer and shall be installed in accordance with the manufacturer’s instructions, the provisions of this code and the requirements determined by the code enforcement official.
Exception: Elevation of the ignition source is not required for appliances that are listed as flammable vapor ignition resistant.
Exception: This section shall not apply to appliance installations complying with Section 305.4.
Exception: The requirements of this section shall not apply where the appliances are protected from motor vehicle impact and installed in accordance with Section 305.3 and NFPA 30A.
Exception: Within a dwelling unit, appliances installed in a compartment, alcove, basement or similar space shall be provided with access by an opening or door and an unobstructed passageway measuring not less than 24 inches (610 mm) wide and large enough to allow removal of the largest appliance in the space, provided that a level service space of not less than 30 inches (762 mm) deep and the height of the appliance, but not less than 30 inches (762 mm), is present at the front or service side of the appliance with the door open.
Permanent ladders installed to provide the required access shall comply with the following minimum design criteria.
Exception: An auxiliary drain pan shall not be required for appliances that automatically shut down operation in the event of a stoppage in the condensate drainage system.
TABLE 308.2a through kREDUCTION OF CLEARANCES WITH SPECIFIED FORMS OF PROTECTION
| 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 308.2(1),
308.2(2), and 308.2(3)]
|WHERE THE REQUIRED CLEARANCE WITH NO PROTECTION FROM APPLIANCE, VENT CONNECTOR, OR SINGLE-WALL METAL PIPE IS:(inches)|
|Allowable clearances with specified protection (inches)|
|Use Column 1 for clearances above appliance or horizontal connector. Use Column 2 for clearances from appliance, vertical connector, and single-wall metal pipe.|
| Above |
| Sides |
| Above |
| Sides |
| Above |
| Sides |
| Above |
| Sides |
| Above |
| Sides |
|1. 31/2-inch-thick masonry wall without ventilated airspace||-||24||-||12||-||9||-||6||-||5|
|2. 1/2-inch insulation board over 1-inch glass fiber or mineral |
|3. 0.024-inch (nominal 24 gage) sheet metal over 1-inch glass |
fiber or mineral wool batts reinforced with wire on rear face
with ventilated airspace
|4. 31/2-inch-thick masonry wall with ventilated airspace||-||12||-||6||-||6||-||6||-||6|
|5. 0.024-inch (nominal 24 gage) sheet metal with ventilated |
|6. 1/2-inch-thick insulation board with ventilated airspace||18||12||9||6||6||4||5||3||3||3|
|7. 0.024-inch (nominal 24 gage) sheet metal with ventilated |
airspace over 0.024-inch (nominal 24 gage) sheet metal with
|8. 1-inch glass fiber or mineral wool batts sandwiched between |
two sheets 0.024-inch (nominal 24 gage) sheet metal with
a. Reduction of clearances from combustible materials shall not interfere with combustion air, draft hood clearance and relief, and accessibility of servicing.
b. 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.
c. Spacers and ties shall be of noncombustible material. No spacer or tie shall be used directly opposite an appliance or connector.
d. For all clearance reduction systems using a ventilated airspace, adequate provision for air circulation shall be provided as described [see Figures 308.2(2) and 308.2(3)].
e. There shall be at least 1 inch between clearance reduction systems and combustible walls and ceilings for reduction systems using ventilated airspace.
f. Where a wall protector is mounted on a single flat wall away from corners, it shall have a minimum 1-inch air gap. To provide air circulation, the bottom and top edges, or only the side and top edges, or all edges shall be left open.
g. Mineral wool batts (blanket or board) shall have a minimum density of 8 pounds per cubic foot and a minimum melting point of 1500°F.
h. Insulation material used as part of a clearance reduction system shall have a thermal conductivity of 1.0 Btu per inch per square foot per hour per °F or less.
i. 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.
j. All clearances and thicknesses are minimum; larger clearances and thicknesses are acceptable.
k. Listed single-wall connectors shall be installed in accordance with the manufacturer’s installation instructions.
"B" equals the reduced clearance permitted in accordance with Table 308.2.2. The protection applied to the construction using combustible material shall extend far enough in each direction to make "C" equal to "A."
FIGURE 308.2(1) EXTENT OF PROTECTION NECESSARY TO REDUCE CLEARANCES FROM APPLIANCE OR VENT CONNECTIONS
FIGURE 308.2(2) WALL PROTECTOR CLEARANCE REDUCTION SYSTEM
FIGURE 308.2(3) MASONRY CLEARANCE REDUCTION SYSTEM