Ducts and air transfer openings.
Municipal Code of Chicago § 14B-7-717
in effect14B-7-717 Ducts and air transfer openings.
The provisions of Section 717 of IBC are adopted by reference with the following modifications:
1. Revise the title of Section 717.1.1 to "Transfer ducts."
2. Delete Section 717.2.1.
3. Revise the first sentence of Section 717.4 to read:
"Fire and smoke dampers shall be provided with a means of access that is large enough to allow inspection and maintenance of the damper and its operating parts."
4. Revise Section 717.5.1 to read:
"717.5.1 Fire walls.
Ducts and air transfer openings permitted in fire walls in accordance with Section 706.11 shall be protected with listed 3-hour-rated fire dampers installed on both sides of the fire wall in accordance with their listing."
5. Revise exception 2 to Section 717.5.2 by replacing "an approved" with "a."
6. Revise Section 717.5.3 by replacing "fire and smoke dampers" with "fire dampers."
7. Delete exceptions 2, 3 and 4 to Section 717.5.2.
8. Revise exception 5 to Section 717.5.2 to read:
"5. Fire dampers are not required in kitchen and clothes dryer exhaust systems."
9. Revise Section 717.5.4 by replacing "Ducts and air transfer openings" with "Air transfer openings."
10. Revise the exceptions to Section 717.5.4 to read:
“Exceptions: In occupancies other than Group H, fire dampers are not required where any of the following apply:
1. Corridor walls in buildings equipped throughout with an automatic sprinkler system in accordance with Section 903.3.1.1 or 903.3.1.2 and the duct is protected as a through penetration in accordance with Section 714.
2. [Reserved.]
3. The duct system is constructed in accordance with the Chicago Mechanical Code and the duct penetrating the wall complies with all of the following requirements:
3.1. The duct shall not exceed 100 square inches (0.06 m2 ).
3.2. The duct shall be constructed of steel not less than No. 26 gage thickness.
3.3. The duct shall not have openings that connect a corridor with adjacent spaces or rooms.
3.4. The duct shall be installed above a ceiling.
3.5. The duct shall not terminate at a wall register in the fire-resistance-rated wall.
3.6. A minimum 12-inch-long (305 mm) by 0.060-inch-thick (1.52 mm) steel sleeve shall be centered in each duct opening. The sleeve shall be secured to both sides of the wall and all four sides of the sleeve with minimum 1 1/2-inch by 1 1/2-inch by 0.060-inch (38 mm by 38 mm by 1.52 mm) steel retaining angles. The retaining angles shall be secured to the sleeve and the wall with No. 10 (M5) screws. The annular space between the steel sleeve and the wall opening shall be filled with mineral wool batting on all sides.
4. Such walls are penetrated by ducted HVAC systems and are in buildings equipped throughout with an automatic sprinkler system in accordance with Section 903.3.1.1 or 903.3.1.2. For the purposes of this exception, a ducted HVAC system shall be a duct system for conveying supply, return or exhaust air as part of the structure’s HVAC system. Such a duct system shall be constructed of sheet steel not less than No. 26 gage thickness and shall be continuous from the air-handling appliance or equipment to the air outlet and inlet terminals.”
11. Revise Section 717.5.4.1 to read:
“717.5.4.1 Corridor ceilings.
A corridor damper shall be provided where corridor ceilings, constructed as required for the corridor walls as permitted in Section 708.4, Exception 3, are penetrated.”*
* Editor’s note – Coun. J. 6-17-26, p. 45214, Art. IV, § 28, failed to underline part of this amendment, and failed to include the end quotation mark. Corrected by the editor. Future legislation will correct if needed.
12. Revise Section 717.5.5 by replacing "at each point" with "adjacent to each point."
13. Add a new exception to Section 717.5.6 to read:
"Exception: Fire dampers are not required in residential kitchen and clothes dryer exhaust systems."
14. Delete Section 717.5.7.
15. Revise Section 717.6.1 by deleting "approved."
16. Revise the exception to Section 717.6.1 by replacing "three floors" with "four floors."
17. Revise Section 717.6.2 by deleting "approved."
18. Revise Section 717.6.3 to read:
"717.6.3 Nonfire-resistance-rated floor assemblies.
Duct systems constructed of materials in accordance with the Chicago Mechanical Code that penetrate nonfire- resistance-rated floor assemblies shall be protected by any of the following methods:
1. A shaft enclosure in accordance with Section 713.
2. The annular space around the penetrating duct is protected with a noncombustible material that resists the free passage of flame and the products of combustion.
Exception: Fire dampers are not required in ducts within individual residential dwelling units."
19. Add a new exception to Section 717.7.
"Exception: Within individual Group R dwelling units or sleeping units."
(Amend Coun. J. 6-17-26, p. 45214, Art. IV, § 28)
Source: City of Chicago, Municipal Code of Chicago (American Legal Publishing, codelibrary.amlegal.com)URL: https://codelibrary.amlegal.com/codes/chicago/latest/chicago_il/0-0-0-2663800Fetched: 10/24/2026