Section 12-A717. DUCTS AND AIR TRANSFER OPENINGS

 

Strike Section 717.5.3 of the International Building Code in its entirety and insert new Section 717.5.3 in its place in the Building Code to read as follows:

 

717.5.3 Shaft enclosures.  Shaft enclosures that are permitted to be penetrated by ducts and air transfer openings shall be protected with listed fire and smoke dampers installed in accordance with their listing.

 

Exceptions:

 

1.Fire and smoke dampers are not required at penetrations of exhaust shafts where steel exhaust subducts extend at least 22 inches (559 mm) vertically in exhaust shafts, provided there is a continuous airflow upward to the outside and the fan is provided with backup standby power.

 

2.Fire dampers are not required where penetrations are tested in accordance with ASTM E 119 or UL 263 as part of the fire-resistance-rated assembly.

 

3. Fire and smoke dampers are not required where ducts are used as part of an approved smoke control system in accordance with Section 909.

 

4.Fire and smoke dampers are not required where the penetrations are in dedicated parking garage exhaust or supply shafts that are separated from other building shafts by not less than 2-hour fire-resistance-rated construction.

 

5.Smoke dampers are not required at penetrations of shafts where the building is equipped throughout with an automatic sprinkler system in accordance with Section 903.3.1.1.

 

6.Fire dampers and combination fire/smoke dampers are not required in kitchen and clothes dryer exhaust systems when installed in accordance with the Mechanical Code.

Strike Section 717.5.4.1 of the International Building Code in its entirety and insert new Section 717.5.4.1 in the Building Code in its place to read as follows:

717.5.4.1 Corridors.  A listed smoke damper designed to resist the passage of smoke shall be provided at each point a duct or air transfer opening penetrates a corridor enclosure required to have smoke and draft control doors in accordance with Section 716.5.3.

 

Exceptions:

 

1. Smoke dampers are not required where the building is equipped with an approved smoke control system in accordance with Section 909, and smoke dampers are not necessary for the operation and control of the system.

 

2.  Smoke dampers are not required in corridor penetrations where the duct is constructed of steel not less than 0.019 inch (0.48 mm) in thickness and there are no openings serving the corridor.

3. Smoke dampers are not required in ducted corridor penetrations where:

 

1. The building is equipped throughout with an automatic sprinkler system in accordance with Section 903.3.1.1 or 903.3.1.2;

 

2. The duct is constructed of steel not less than 0.019 inch (0.48 mm) in thickness;

 

3. The ducted system supplies outdoor air only to the corridor and to air handling units that serve spaces adjoining the corridor through ducted connections: and

 

4. The outdoor air supply fan is designed to provide a continuous airflow.

 

 

authority

Section 10 of the Construction Codes Approval and Amendments Act of 1986 (Act), effective March 21, 1987 (D.C. Law 6-216; D.C. Official Code § 6-1409 (2012 Repl.)) and Mayor’s Order 2009-22, dated February 25, 2009, as amended.

source

Final Rulemaking published at 61 DCR 2782 (March 28, 2014 – Part 2).

EditorNote

The District of Columbia Building Code (2013), referred to as the “Building Code,” consists of the 2012 edition of the International Building Code as amended by the District of Columbia Building Code Supplement (2013)(12 DCMR A). The International Building Code is copyrighted by the International Code Council and therefore is not republished here. However, a copy of the text may be obtained at:http://publicecodes.cyberregs.com/icod/ibc/2012/index.htm?bu=IC-P-2012-000001&bu2=IC-P-2012-000019.