503.5.4 Chimney termination.
FGC § 503.5.4
Chimneys serving gas-fired equipment shall comply with the appliance listing, the manufacturer's instructions, Figure 503.5.4 and the following requirements: 1. Chimneys, vents and flues serving appliances or fireplaces with outlet temperatures less than 600°F (315.6 °C) shall extend not less than 3 feet (914.4 mm) above the highest construction, such as a roof ridge, parapet wall, or penthouse within 10 feet (3048 mm) of the chimney, vent or flue outlet, whether the construction is on the same building as the chimney or on another building. However, such constructions do not include other chimneys, vents, or open structural framing. Any chimneys, vents or flues located beyond 10 feet (3048 mm) from such construction, but not more than the distance determined by Equation 5-1, shall be at least as high as the construction.
2.Chimneys serving appliances or fireplaces with outlet temperatures between 600°F (315.6°C) and 1,000°F (537.8°C) shall extend not less than 10 feet (3048 mm) above the highest construction, such as a roof ridge, or parapet wall or penthouse within 20 feet (6096 mm) of the chimney outlet, whether the construction is on the same building as the chimney or on another building. However, such constructions do not include other chimneys, and vents or open structural framing. Any chimneys located beyond 20 feet (6096 mm) from such construction, but not more than the distance determined by Equation 5-1, shall be at least as high as the construction.
3.Chimneys serving appliances or fireplaces with outlet temperatures greater than 1,000°F (537.8°C) shall extend not less than 20 feet (6096 mm) above the highest construction, such as roof ridge, parapet wall, penthouse, or other obstruction within 50 feet (15 240 mm) of the chimney outlet, whether the construction is on the same building as the chimney or in another building. However, such constructions do not include other chimneys, vents, or open structural framing. Any chimneys located beyond 50 feet (15 240 mm) from such construction, but not more than the distance determined by Equation 5-1, shall be at least as high as the construction.
4.Termination caps shall not be permitted. A drain shall be installed in accordance with Section 801.22 of the New York City Mechanical Code. A positive means shall be provided to prevent water from entering the appliance. Exception: Termination caps shall be permitted on listed factory-built chimneys unless otherwise prohibited by the New York City Air Pollution Control Code.
5.Decorative shrouds shall not be installed at the termination of factory-built chimneys except where such shrouds are listed and labeled for use with the specific factory-built chimney system and are installed in accordance with the manufacturers' instructions.
6.The following equation shall be used for determining the distances referred to in Items 1, 2 and 3 of this section. D = F x √A (Equation 5-1) where: D=Distance, in feet, measured from the center of the chimney, vent or flue outlet to the nearest edge of the construction. If a single chimney is divided into multiple smaller flues or chimneys, measure from the center of the chimney outlet that is closest to the nearest edge of the construction.F=Value determined from table belowA=Free area, in square inches, of chimney flue space outlet. If a single chimney is divided into multiple smaller flues or chimneys, the total aggregate free area of such flue and chimney outlets shall be used to calculate "A". "F" Factor for Determining Chimney Distances Type of Fuel"F" Factor 600°F (315.6°C)and less600°F (315.6°C) to1,000°F (537.8°C)Greater than 1,000°F (537.8°C)Gas 2 2 3 For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm. Figure 503.5.4Typical Termination Locations for Chimneys and Single-Wall Metal Pipes Serving Residential-Type and Low-Heat Appliances (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.
