803.10.3 Connection.

The connector shall extend to the inner face of the chimney or vent liner, but not beyond. A connector entering a masonry chimney shall be cemented to masonry in an approved manner. Where thimbles are installed to facilitate removal of the connector from the masonry chimney, the thimble shall be permanently cemented in place with high-temperature cement.

803.10.4 Connector pass-through.

Chimney connectors shall not pass through any floor or ceiling, nor through a fire-resistance-rated wall assembly. Chimney connectors shall not pass through walls or partitions constructed of combustible material to reach a chimney or vent, except where such chimney connector complies with Section 803.10.4.1 or 803.10.4.2.

Table 803.10.4
Chimney Connector Systems and Clearances to Combustible Wall Materials for Heating Appliances a, b, c, d, e  

 

System A (12-inch clearance)	A 3.5-inch-thick brick wall shall be framed into the combustible wall. A 0.625-inch-thick fire-clay liner (ASTM C 315 or equivalent) e shall be firmly cemented in the center of the brick wall maintaining a 12-inch clearance to combustibles. The clay liner shall run from the outer surface of the bricks to the inner surface of the chimney liner.
System B (9-inch clearance)	A labeled solid-insulated factory-built chimney section (1-inch insulation) the same inside diameter as the connector shall be utilized. Sheet steel supports cut to maintain a 9-inch clearance to combustibles shall be fastened to the wall surface and to the chimney section. Fasteners shall not penetrate the chimney flue liner. The chimney length shall be flush with the masonry chimney liner and sealed to the masonry with water-insoluble refractory cement. Chimney manufacturers' parts shall be utilized to securely fasten the chimney connector to the chimney section.
System C (6-inch clearance)	A sheet metal (minimum No. 24 gage) ventilated thimble having a minimum thickness of 0.0236 inch (No. 24 gage) having two 1-inch air channels shall be installed. Steel supports shall be cut to maintain a 6-inch clearance with a sheet steel chimney connector between the thimble and combustibles. The chimney connector and steel supports shall have a minimum thickness of 0.0236 inch (No. 24 gage). One side of the support shall be fastened to the wall on all sides. Glass-fiber insulation shall fill the 6-inch space between the thimble and the supports.
System D (2-inch clearance)	A labeled solid-insulated factory-built chimney section (1-inch insulation) with a diameter 2 inches larger than the chimney connector shall be installed with a steel chimney connector having a minimum thickness of 0.0236 inch (No. 24 gage). Sheet steel supports shall be positioned to maintain a 2-inch clearance to combustibles and to hold the chimney connector to ensure that a 1-inch airspace surrounds the chimney connector through the chimney section. The steel support shall be fastened to the wall on all sides and the chimney section shall be fastened to the supports. Fasteners shall not penetrate the liner of the chimney section.

 

For SI: 1 inch = 25.4 mm, 1.0 Btu × in/ft 2 • h • °F = 0.144 W/m 2 • °K.

a.   Insulation material that is part of the wall pass-through system shall be noncombustible and shall have a thermal conductivity of 1.0 Btu - in/ft 2 • h • °F or less.

b.   All clearances and thicknesses are minimums.

c.   Materials utilized to seal penetrations for the connector shall be noncombustible.

d.   Connectors for all systems except System B shall extend through the wall pass-through system to the inner face of the flue liner.

e.   ASTM C 315.

(Am. L.L. 2023/077, 6/11/2023, eff. 6/11/2023)

Editor's note: For related unconsolidated provisions, see Appendix A at L.L. 2023/077.

803.10.4.1 Manufactured insulated chimney connectors.

Manufactured insulated chimney connectors that pass through walls or partitions of combustible construction must comply with the following:

   1.   The connector is labeled for wall pass-through and is installed in accordance with the manufacturer's instructions; or

   2.   The connector is put through a device labeled for wall pass-through; or

   3.   The connector has a diameter not larger than 10 inches (254 mm) and is installed in accordance with one of the methods in Table 803.10.4. Concealed metal parts of the pass-through system in contact with flue gases shall be of stainless steel or equivalent material that resists corrosion, softening or cracking up to 1,800°F (982°C).

(Am. L.L. 2023/077, 6/11/2023, eff. 6/11/2023)

Editor's note: For related unconsolidated provisions, see Appendix A at L.L. 2023/077.

803.10.4.2 Field-applied insulation for chimney connectors.

Chimney connectors of appliances with flue gas temperatures less than 500°F (260°C) that pass through walls or partitions of combustible construction shall be insulated with a field-applied flexible wrap assembly tested in accordance with either ASTM E 2816 or ASTM E 2336. The connector shall comply with all of the following:

   1.   The insulated vent connectors pass-through assemblies and through penetration assemblies shall be tested for F and T ratings in accordance with ASTM E 814. The F and T rating of the assembly shall be equal to or exceed the fire-resistance rating of the mechanical/boiler room.

   2.   Bracing and supports shall be of noncombustible material securely attached to the structure and designed to carry gravity and seismic loads within the stress limitations of Chapter 16 of the New York City Building Code. Bolts, screws, rivets and other mechanical fasteners shall not penetrate connector walls.

   3.   Insulated vent connector pass-through assemblies shall not pass through ceilings or floors.

   4.   Insulated vent connector pass-through assemblies shall not run through occupied spaces, corridors, sleeping rooms and spaces with hazardous materials.

   5.   Insulated vent connector pass-through assemblies material shall meet the requirements for minimum chimney connector thicknesses for medium and high-heat appliances in accordance with Table 803.9(2).

   6.   Insulated vent connector pass-through assemblies fittings shall be welded or shall be factory fabricated UL listed construction suitable for external flexible wrap insulation.

   7.   The draft calculations shall account for the insulating value of the field-applied flexible wrap insulation.

803.10.5 Pitch.

Connectors shall rise vertically to the chimney or vent with a minimum pitch equal to one-fourth unit vertical in 12 units horizontal (2-percent slope).

803.10.6 Clearances.

Connectors shall have a minimum clearance to combustibles in accordance with Table 803.10.6. The clearances specified in Table 803.10.6 apply, except where the listing and labeling of an appliance specifies a different clearance, in which case the labeled clearance shall apply. The clearance to combustibles for connectors shall be reduced only in accordance with Section 308 or via the use of a listed chimney or vent connector system.

Table 803.10.6
Connector Clearances to Combustibles

Type of Appliance	Minimum Clearance (inches)
Domestic-type appliances
Chimney and vent connectors
Electric and oil incinerators	18
Oil and solid fuel-burning appliances	18
Oil appliances labeled for venting with Type L vents	9
Commercial, industrial-type appliances
Low-heat appliances
Chimney connectors
Oil and solid fuel boilers, furnaces and water heaters	18
Oil unit heaters	18
Other low-heat industrial appliances	18
Medium-heat appliances
Chimney connectors
All oil and solid fuel-burning appliances	36
High-heat appliances
Masonry or metal connectors
All oil and solid fuel-burning appliances	In accordance with NFPA 211

 

For SI: 1 inch = 25.4 mm.

Section MC 804: Direct-Vent, Integral Vent and Mechanical Draft Systems

804.1 Direct-vent terminations.

Vent terminals for direct-vent appliances shall be installed in accordance with the manufacturer's instructions. In addition, direct vent terminations shall comply with the following requirements:

   1.   Where located adjacent to walkways, the termination shall be not less than 7 feet (2133.6 mm) above the level of the walkway.

   2.   Vents shall terminate at least 3 feet (914.4 mm) above any forced air inlet, other than the forced air inlet for the subject direct vent appliance, located within 10 feet (3048 mm).

   3.   The vent system shall terminate at least 4 feet (1219.2 mm) below, 4 feet (1219.2 mm) horizontally from or 1 foot (304.8 mm) above any door, window or gravity air inlet into the building.

   4.   The vent termination point shall not be located closer than 3 feet (914.4 mm) to an interior corner formed by two walls perpendicular to each other.

   5.   The vent termination shall not be mounted directly above or within 3 feet (914.4 mm) horizontally from any gas or electric metering, regulating, venting relief equipment or other building opening.

   6.   The bottom of the vent termination shall be located at least 36 inches (914.4 mm) above finished grade.

   7.   The maximum heat input of an appliance served by single horizontal vent termination shall be 350,000 Btu/h (102.6 kW), unless otherwise approved by the commissioner.

   8.   The maximum heat input of all appliances served by horizontal vent terminations located within a 10 foot (3048 mm) radius shall be 350,000 Btu/h (102.6 kW), unless otherwise approved by the commissioner.

   9.   The vent termination shall be located a minimum of 4 feet (1219.2 mm) from the lot line or from adjacent buildings. The termination shall be installed in accordance with the vent manufacturer's instructions.

Editor's note: For related unconsolidated provisions, see Appendix A at L.L. 2014/051.