401.4.1 Required Dampers in Intake Openings

An outdoor air intake opening with gross area of more than 144 square inches (0.0929 m²) shall be provided with fire dampers and smoke dampers, or combined fire and smoke dampers when such opening is located as follows:

1. Less than 30 feet (9144 mm) above grade.
2. Less than 30 feet (9144 mm) in any direction from any opening in another building.
3. Less than 15 feet (4572 mm) from a lot line.
4. Less than 50 feet (15 240 mm) above and less than 50 feet (15 240 mm) in any direction from a roof constructed of combustible material or a building in which the exterior walls are constructed wholly or partly of wood.
5. Where fire dampers are required by Section 607.5.6.

Exceptions:

1. Smoke dampers shall not be required for outdoor air intake openings installed in any construction required to have a fire-resistance rating that is less than 2 hours.
2. Smoke dampers shall not be required for outdoor air intake openings of systems greater than 15,000 cfm (7.1 m³/s) which are provided with smoke dampers in accordance with Chapter 6 of this code and arranged so as to not introduce smoke into the building or space in which the equipment is located.