Ducts shall have a clearance to combustibles in accordance with Table 18-28-510.8.2. Exhaust gases having temperatures in excess of 600°F (316°C) shall be exhausted to a chimney in accordance with Section 18-28-511.2.
Type of Exhaust or Temperature of Exhaust (°F) | Clearance to Combustibles (Inches) |
Less than 100 | 1 |
100 – 600 | 12 |
Flammable vapors | 6 |
For SI: 1 inch = 25.4 MM; °C = [(°F) - 32]/1.8.
(Amend Coun. J. 11-8-12, p. 38872, § 320)