June 7, 2012 PARTIES INTERESTED IN HVAC DUCT ENCLOSURE ASSEMBLIES

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1 June 7, 2012 TO: PARTIES INTERESTED IN HVAC DUCT ENCLOSURE ASSEMBLIES SUBJECT: Revisions to the Acceptance Criteria for Metallic HVAC Duct Enclosure Assemblies, Subject AC R1 (MB/CA) Dear Colleague: We are enclosing the revised ICC-ES Acceptance Criteria for Metallic HVAC Duct Enclosure Assemblies (AC179), which was approved by the Evaluation Committee during the June 2012 hearings. The criteria was approved with the revisions proposed in our letter dated April 27, 2012 (new Sections 3.7 and 5.6), and with an editorial revision to Section 3.5. The revisions are related to use of the enclosure materials to protect ducts used in pressurization systems in stairways and elevator hoistways under IBC Sections and The changes approved by the committee expand the scope of the criteria. Report applicants with applications currently under review may request an expansion of the scope of their review, and current report holders may apply to revise their existing reports, to include this new recognition. Thank you for your interest. If you have any questions, please contact Michael Beaton, P.E., senior vice president, at (800) , extension 3289, or by at Yours very truly, GGN/md Enclosure cc: Evaluation Committee Gary G. Nichols, P.E., SECB Vice President

2 (800) (562) A Subsidiary of the International Code Council ACCEPTANCE CRITERIA FOR METALLIC HVAC DUCT ENCLOSURE ASSEMBLIES AC179 Approved June 2012 Previously revised October 2011, April 2008, October 2005, February 2005 PREFACE Evaluation reports issued by ICC Evaluation Service, LLC (ICC-ES), are based upon performance features of the International family of codes. (Some reports may also reference older code families such as the BOCA National Codes, the Standard Codes, and the Uniform Codes.) Section of the International Building Code reads as follows: The provisions of this code are not intended to prevent the installation of any materials or to prohibit any design or method of construction not specifically prescribed by this code, provided that any such alternative has been approved. An alternative material, design or method of construction shall be approved where the building official finds that the proposed design is satisfactory and complies with the intent of the provisions of this code, and that the material, method or work offered is, for the purpose intended, at least the equivalent of that prescribed in this code in quality, strength, effectiveness, fire resistance, durability and safety. This acceptance criteria has been issued to provide interested parties with guidelines for demonstrating compliance with performance features of the codes referenced in the criteria. The criteria was developed through a transparent process involving public hearings of the ICC-ES Evaluation Committee, and/or on-line postings where public comment was solicited. New acceptance criteria will only have an approved date, which is the date the document was approved by the Evaluation Committee. When existing acceptance criteria are revised, the Evaluation Committee will decide whether the revised document should carry only an approved date, or an approved date combined with a compliance date. The compliance date is the date by which relevant evaluation reports must comply with the requirements of the criteria. See the ICC-ES web site for more information on compliance dates. If this criteria is a revised edition, a solid vertical line ( ) in the margin within the criteria indicates a change from the previous edition. A deletion indicator ( ) is provided in the margin where significant wording has been deleted. ICC-ES may consider alternate criteria for report approval, provided the report applicant submits data demonstrating that the alternate criteria are at least equivalent to the criteria set forth in this document, and otherwise demonstrate compliance with the performance features of the codes. ICC-ES retains the right to refuse to issue or renew any evaluation report, if the applicable product, material, or method of construction is such that either unusual care with its installation or use must be exercised for satisfactory performance, or if malfunctioning is apt to cause injury or unreasonable damage. NOTE: The Preface for ICC-ES acceptance criteria was revised in July 2011 to reflect changes in policy. Acceptance criteria are developed for use solely by ICC-ES for purpose of issuing ICC-ES evaluation reports. Copyright 2012

3 ACCEPTANCE CRITERIA FOR METALLIC HVAC DUCT ENCLOSURE ASSEMBLIES (AC179) 1.0 INTRODUCTION 1.1 Purpose: The purpose of this acceptance criteria is to establish requirements for fire protection enclosure systems, applied to metallic HVAC ducts which provide an alternate to required fire-resistance-rated shafts or an alternate to required fire dampers in specific locations, to be recognized in an ICC Evaluation Service, LLC (ICC- ES) evaluation report under the 2012, 2009 and 2006 International Building Code (IBC) and the 2012, 2009 and 2006 International Mechanical Code (IMC). Bases of recognition are 2012 IBC Sections , 713.1, 714, 717, 909 and ; 2009 IBC Sections , 708.2, 713, 716, and ; 2006 IBC Sections , 707.2, 712, 716 and ; and IMC Sections and Scope: This criteria includes requirements for applied, rigid or flexible fire protection enclosure systems (including stability, integrity, and insulation) that are installed on or as part of metallic HVAC ducts, yielding an alternate to required fire-resistance-rated shafts which are required to be protected from both internal and external fire exposure, or required fire dampers. This criteria provides an alternate to shaft enclosures for vertical ducts, and an alternate to fire dampers in horizontal ducts (penetrating fire barriers, fire partitions, and or smoke barriers) and vertical ducts connecting not more than two stories. This criteria is applicable to conventional shaft walls protecting metallic HVAC ducts. This criteria is applicable to ducts that are part of a pressurization system for elevator hoistways and stairways.this criteria is not applicable to commercial kitchen hood ventilation systems (grease ducts), non-metallic ducts, flexible air ducts, or shafts used for egress. The metallic HVAC duct system complying with this criteria may be installed with zero clearance from the insulating materials to combustibles. 1.3 Codes and Reference Standards: Reference Documents: , 2009 and 2006 International Building Code (IBC), International Code Council , 2009 and 2006 International Mechanical Code (IMC), International Code Council ASTM C411-05, Test Method for Hot-surface Performance of High-temperature Thermal Insulation, ASTM ASTM C518-10, Standard Test Method for Steady State Heat Flux Measurements and Thermal Transmission Properties by Means of the Heat Flow Meter Apparatus, ASTM ASTM E84-09, Standard Test Method for Surface Burning Characteristics of Building Materials, ASTM ASTM E Test Method for Behavior of Materials in a Vertical Tube Furnace at 750 C, ASTM ASTM E814-08b Standard Test Method for Fire Tests of Through-penetration Fire Stops, ASTM ASTM E , Standard Practice for Specimen Preparation and Mounting of Pipe and Duct Insulation Materials to Assess Surface Burning Characteristics, ASTM ASTM E , Standard Test Methods for Fire Resistive Metallic HVAC Duct Systems, ASTM UL , Standard for Test for Surface Burning Characteristics of Building Materials, Underwriters Laboratories LLC UL , Fire Tests of Through-Penetration Firestops - with revisions through March 2010, Underwriters Laboratories LLC. 1.4 Definitions: HVAC Duct: For the purposes of these criteria, a metallic heating, ventilating, or air-conditioning (HVAC) duct fabricated in accordance with Chapter 6 the IMC, which is often referred to as an air duct Shaft: An enclosed space extending though one or more stories of a building, connecting vertical openings in successive floors, or floors and roof Shaft Enclosure: The walls or construction forming the boundaries of a shaft. For HVAC ducts penetrating more than two floors, 2012 IBC Section 717.6, and 2009 and 2006 IBC Section require shaft enclosure walls to be fire-resistance-rated in accordance with 2012 IBC Section 713.4, 2009 IBC Section and 2006 IBC Section Section of the 2012 IBC, Section of the 2009 IBC and Section of the 2006 IBC require the rating to be one or two hours, depending on the number of floors penetrated by the shaft. Section 713 of the 2012 IBC, Section 708 of the 2009 IBC and Section 707 of the 2006 IBC require the shaft enclosure walls to satisfy the requirements of a fire barrier in accordance with 2012 and 2009 IBC Section 707 and 2006 IBC Section 706, or horizontal assemblies in accordance with 2012 IBC Section 714.4, 2009 IBC Section 712 and 2006 IBC Section 711, or both. Section requires all fire-resistance-rated walls to be assigned a rating based on fire exposure from the side with the least resistance. Fire-resistance-rated shaft enclosures are required for vertical HVAC duct penetrations of fire-resistance-rated floors or floor/ceiling assemblies, with the following exceptions: (1) In occupancies other than groups I-2 and I-3, a fire damper placed at the floor line is allowed when connecting not more than two stories; or (2) a maximum 4-inch-diameter HVAC duct is allowed to connect up to three stories without damper or shaft protection, provided all the exceptions to 2012 IBC Section , and 2009 and 2006 IBC Section , are satisfied. 2.0 BASIC INFORMATION 2.1 General: The following information shall be submitted: Product Description: Information on the manufacturing process of the fire protection enclosure system; method of packaging and product identification; specifications and/or mill order certificates for steel duct material, including gage, thickness and galvanization details. 2

4 ACCEPTANCE CRITERIA FOR METALLIC HVAC DUCT ENCLOSURE ASSEMBLIES (AC179) Installation Instructions: Description of fasteners, including manufacturer s type and method of application; details of duct supports; description of any covering or linings for the insulation material Packaging and Identification: A description of the method of packaging and field identification of the fire protection enclosure system. Identification provisions shall include the evaluation report number, the name or logo of the inspection agency, and a description of safety labeling. 2.2 Testing Laboratories: Testing laboratories shall comply with Section 2.0 of the ICC-ES Acceptance Criteria for Test Reports (AC85) and Section 4.2 of the ICC-ES Rules of Procedure for Evaluation Reports. 2.3 Test Reports: Test reports shall comply with AC85. Test reports shall include test specimen description, details of the test method, manner of testing, test results, calculated results, and photographs. The test reports shall also include information required by the applicable standard. 2.4 Product Sampling: Sampling of the duct insulation material for tests under this criteria shall comply with Section 3.1 of AC TEST METHODS AND PERFORMANCE REQUIREMENTS 3.1 General: Fire protection enclosure systems tested under this criteria shall satisfy the requirements of Sections 3.2, 3.3, 3.4, and 3.5 and/or Surface-burning Characteristics: Fire protection enclosure systems, including vapor barriers and adhesives, when used, shall have a flame-spread index of not more than 25 and a smoke-developed index of not more than 50, when tested in accordance with ASTM E84 or UL 723, using the specimen preparation and mounting procedures of ASTM E2231. Duct coverings shall not flame, flow, smolder or smoke when tested in accordance with ASTM C411 at the temperature to which they will be exposed in service. The test temperature shall not fall below 250 F (121 C). 3.3 Non-combustibility Tests: The duct-enclosure material, excluding its duct covering, shall be tested for compliance with ASTM E136, and the material shall be designated as passing the test. 3.4 Durability Tests: The purpose of durability tests is to simulate the effects of long-term exposure to typical in-service conditions on the thermal transmission properties of the duct covering materials A minimum of eight samples of the duct enclosure material is needed, in the thickness intended for use. The length and width of the test specimen shall comply with ASTM C518, and all specimens shall be conditioned for a minimum of 24 hours at 75 F ± 5 F (23.8 C ± 2.7 C) with a relative humidity of 50 ± 5 percent Four samples are exposed to the effects of temperature aging. An additional four samples are reserved as control samples for comparison. The temperature-aging samples are placed on a rack in a vertical position, with a clearance, between samples, of between 3 / 8 and 3 / 4 inch (9.5 to 19.1 mm). The rack is 3 placed into an oven that has been preheated to a temperature of 300 F (149 C). After 12 hours of exposure, the oven is shut off and the specimens are allowed to cool for 12 hours. This cycle is repeated 10 times. On completion of the final cycle, the specimens are removed from the oven and allowed to cool for a period of two hours at standard atmospheric conditions Thermal conductivity properties of temperature-aged samples and control samples are determined in accordance with ASTM C518. The average thermal conductivity of the temperature-aged samples shall be reported as a percentage of the average thermal conductivity of control samples Conditions of Acceptance: When compared to results for control specimens, thermal conductivity shall not increase by more than10 percent as a result of temperature aging. 3.5 Ducts with Fire Protection Enclosure Systems in lieu of Fire-resistance-rated Shaft Walls: To establish equivalence with fire-resistance-rated vertical shaft enclosures and fire dampers, the proprietary enclosure material and duct assembly shall be tested in accordance with ASTM E2816, Condition B Fire exposure from the outside of the vertical HVAC duct system without openings, and Condition D Fire exposure from the outside with hot gases entering the inside of the vertical HVAC duct system. These test methods provide a means for evaluating a vertical HVAC duct system with a horizontal connection, without openings exposed to fire (Condition B) and with unprotected openings exposed to fire (Condition D), passing through a horizontal fireseparating element protected with a through-penetration firestop system. The through-penetration firestop shall comply with the requirements of ASTM E814 or UL 1479 for the same period of time as indicated for the fireengulfment test Conditions B and D. The test specimen shall be representative of its intended construction, application, and installation. The test specimen configuration shall consist of metallic duct material of the thinnest gage, of the maximum cross-sectional area (and maximum duct dimension), with the minimum thickness fire protection enclosure system, for which recognition is sought. 3.6 Fire Protection for Horizontal and Vertical HVAC Ducts with Dedicated Fire Protection Systems in Lieu of Required Fire Dampers: The intent of this section is to establish equivalence of duct fire protection systems to the level of protection provided by required fire dampers, for specific applications as noted herein. The fire protection system, consisting of the proprietary protection materials or assemblies, including supports, shall be tested in accordance with and shall meet the conditions of acceptance of ASTM E Horizontal Ducts: ASTM E2816, Condition A Fire exposure from the outside of the horizontal HVAC duct system without openings, and Condition C Fire exposure from the outside with hot gases entering the inside of the horizontal HVAC duct system with unprotected openings. Recognition under Section is limited to horizontal ducts penetrating fire-resistance-rated fire barriers, fire partitions and/or smoke barriers each with a maximum fire-resistance rating of two hours. The through-penetration firestop shall comply with the requirements of ASTM E814 or UL 1479 for the same

5 ACCEPTANCE CRITERIA FOR METALLIC HVAC DUCT ENCLOSURE ASSEMBLIES (AC179) period of time as indicated for the fire-engulfment test Conditions A and C. The test shall be performed for horizontal applications, with metallic duct material of the thinnest gage, of the maximum cross-sectional area (and maximum duct dimension), with the minimum thickness fire protection enclosure system, for which recognition is sought Vertical Ducts: ASTM E2816, Condition B Fire exposure from the outside of the vertical HVAC duct system without openings, and Condition D Fire exposure from the outside with hot gases entering the inside of the vertical HVAC duct system with unprotected openings. Recognition under Section is limited to vertical ducts that connect multiple stories with a maximum fireresistance rating of two hours. The through-penetration firestop shall comply with the requirements of ASTM E814 or UL 1479 for the same period of time as indicated for the fire-engulfment test Conditions B and D. The test shall be performed for vertical applications, with metallic duct material of the thinnest gage, of the maximum crosssectional area (and maximum duct dimension), and with the minimum thickness fire protection enclosure system, for which recognition is sought. 3.7 Fire Protection for Horizontal and Vertical Stair or Elevator Hoistway Pressurization Systems with Dedicated Fire Protection Systems Ducts that are part of elevator hoistway pressurization systems under 2012 IBC Section or stair pressurization systems under 2012 IBC Section , shall meet the conditions of acceptance of ASTM E2816, Condition A Fire exposure from the outside of the horizontal HVAC duct system without openings, or Condition B Fire exposure from the outside of the vertical HVAC duct system without openings, or both orientations (Conditions A and B). The duct enclosure system shall consist of the proprietary protection materials or assemblies, including supports. 4.0 QUALITY CONTROL 4.1 The products shall be manufactured under an approved quality control program with inspections by an inspection agency accredited by the International Accreditation Service (IAS) or otherwise acceptable to ICCES. 4.2 Quality documentation complying with the ICC-ES Acceptance Criteria for Quality Documentation (AC 10) shall be submitted. 4.3 A qualifying inspection shall be conducted at each manufacturing facility when required by the ICC-ES Acceptance Criteria for Inspections and Inspection Agencies (AC304). 5.0 EVALUATION REPORT RECOGNITION The evaluation report shall include the following conditions of use: 5.1 The system shall bear the words Fire-Resistance- Rated Protective Duct Assembly - DO NOT REMOVE. The wording shall be visible after the fire protection system is installed. 5.2 Substitution of fire protection systems for required fire dampers under Section 3.6 is limited to horizontal ducts penetrating fire-resistance-rated fire barriers, fire partitions and/or smoke barriers, shaft enclosures, and to vertical ducts, each with a maximum fire-resistance rating of two hours. 5.3 For fire protection systems qualified under Section 3.6, openings are not permitted for a minimum distance of 6 feet ( mm) from each side of the fire-resistancerated assembly. 5.4 When qualification is under Sections 3.2, 3.3, 3.5 and either Section or Section 3.6.2, or both, the evaluation report shall include one or both of the following conditions of use: When penetrating fire-resistance-rated wall combustibles only when the ASTM E814 or UL 1479 F- rating equals or exceeds the fire-resistance rating of the wall assembly, as required by the applicable code. See 2012 IBC Section , 2009 IBC Section or 2006 IBC Section When penetrating fire-resistance-rated horizontal combustibles only when the ASTM E814 or UL 1479 F- rating and T-rating equal or exceed the fire-resistancerating of the horizontal assembly, as required by the applicable code. For exceptions, see 2012 IBC Section , 2009 IBC Section or 2006 IBC Section Smoke dampers must be installed as required by the applicable code. 5.6 When qualification is under Section 3.7, the evaluation report shall include the following condition of use: When penetrating fire-resistance-rated wall combustibles only when the F-rating and T-rating equal or exceed the fire-resistance-rating of the fire-resistancerated fire barrier, fire partition, or smoke barrier being penetrated. 4