NFPA® 90A Standard for the Installation of Air-Conditioning and Ventilating Systems Handbook 2015

90A

NFPA®, 1 Batterymarch Park, Quincy, MA 02169-7471, USA An International Codes and Standards Organization NFPA® 90A Standard for the Installation of Air-Conditioning and Ventilating Systems Handbook 2015

Second Edition

Annotated by Allan Fraser

NFPA, 1 Batterymarch Park, Quincy, MA 02169-7471 An International Codes and Standards Organization Copyright © 2014 National Fire Protection Association® One Batterymarch Park Quincy, Massachusetts 02169-7471

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ISBN: 978-145591124 90A–1

NFPA® 90A

Standard for the Installation of Air-Conditioning and Ventilating Systems

2015 Edition

This edition of NFPA 90A, Standard for the Installation of Air-Conditioning and Ventilating Systems, was prepared by the Technical Committee on Air Conditioning. It was issued by the Standards Council on April 29, 2014, with an effective date of May 19, 2014, and supersedes all previous editions. This edition of NFPA 90A was approved as an American National Standard on May 19, 2014. L Origin and Development of NFPA 90A This standard dates from 1899, when committee attention was first given to blower and exhaust systems. Prior to 1936, the subject of air conditioning was covered in NFPA standards on blower systems. In 1937, it was decided to prepare a separate standard on air-conditioning, warm air heating, and ventilating systems. This standard was initially adopted in 1937 with subsequent amendments in 1938, 1939, 1940, 1942, 1950, 1952, 1955, 1956, 1960, 1961, 1963, 1964, 1965, 1968, 1971, 1973, 1976, 1980, 1984, and 1989. The 1993 and 1996 editions were reconfirmations of the 1989 edition. The 1999 edition contained changes that were mainly editorial in nature. The 2002 edition incorporated format changes to comply with the Manual of Style for NFPA Technical Committee Documents and new provisions for the removal of accessible abandoned materials in concealed spaces and plenums. The only changes to the 2006 edition were to update “flame spread rating” to “flame spread index.” The major change in the 2009 edition was to replace the references to NFPA 255 with ANSI/UL 723 and ASTM E 84, since NFPA 255 had been withdrawn. All three test standards are quite similar. The changes in the 2012 edition were for the purposes of updating the editions of the referenced standards. For the 2015 edition, the changes that have been made consist of primarily editorial alterations, reference updates, and clarifications of existing language. A section and test method for Air Dispersion Systems has also been added.

NFPA and National Fire Protection Association are registered trademarks of the National Fire Protection Association, Quincy, Massachusetts 02169. 90A–2 INSTALLATION OF AIR-CONDITIONING AND VENTILATING SYSTEMS

Technical Committee on Air Conditioning

Ralph D. Gerdes, Chair Ralph Gerdes Consultants, LLC, IN [SE]

Charles E. Altizer, Virginia State Fire Marshal’s Office, Charles C. Holt, National Energy Management Institute, VA [E] VA [L] Rep. International Fire Marshals Association Rep. Sheet Metal Workers’ International Association Ramzi A. Amawi, Intertek Testing Services, OH [RT] Eli P. Howard, III, Sheet Metal & Air Conditioning Jesse J. Beitel, Hughes Associates, Inc., MD [SE] Contractors Natl. Assn., VA [IM] James S. Buckley, Jacobs, TX [IM] Anthony Hurst, Mason & Hanger, KY [SE] Rep. American Society for Heating, Refrigeration & Air Marvin A. Koerber, ATCO Rubber Products Inc., SC [M] Conditioning Engineers Inc. Rep. Air Diffusion Council Merton W. Bunker, Jr., U.S. Department of State, VA [U] William E. Koffel, Koffel Associates, Inc., MD [M] Laurence W. Caraway, Jr., Kitchen Klean Inc., NH [IM] Rep. Society of the Plastics Industry, Inc. Rep. National Air Duct Cleaners Association Richard E. Loyd, R & N Associates, AZ [M] Michael Earl Dillon, Dillon Consulting Engineers, Inc., Rep. American Iron and Steel Institute CA [SE] Timothy J. Orris, AMCA International, Inc., IL [M] James T. Dollard, Jr., IBEW Local Union 98, PA [L] Rep. International Brotherhood of Electrical Workers Rep. Air Movement & Control Association Thomas M. Dusza, The RJA Group, CA [SE] Thomas E. Ponder, CertainTeed Corporation, PA [M] Jonathan Flannery, AHA-ASHE, AR [U] Rep. North American Insulation Manufacturers Thomas P. Hammerberg, Automatic Fire Alarm Association Association, Inc., GA [M] Suresh K. Shah, U.S. Department of Health & Human Rep. Automatic Fire Alarm Association, Inc. Services, TX [U] J. C. Harrington, FM Global, MA [I] Dwayne E. Sloan, UL LLC, NC [RT] Jonathan Hartsell, Rodgers, NC [IM] George A. Straniero, AFC Cable Systems, Inc., NJ [M] Marcelo M. Hirschler, GBH International, CA [M] Rep. National Electrical Manufacturers Association Rep. American Fire Safety Council/Plenum Cable Randolph W. Tucker, ccrd partners, TX [SE] Assn. Robert A. Wessel, Gypsum Association, MD [M]

Alternates

Diane B. Copeland, Dillon Consulting Engineers, Inc., Randall K. Laymon, UL LLC, IL [RT] CA [SE] (Alt. to D. E. Sloan) (Alt. to M. E. Dillon) Harold C. Ohde, IBEW-NECA Technical Institute, IL [L] Charles C. Cottrell, North American Insulation (Alt. to J. T. Dollard, Jr.) Manufacturers Assn., VA [M] Isaac I. Papier, Honeywell, Inc., IL [M] (Alt. to T. E. Ponder) (Alt. to G. A. Straniero) Michael A. Gardner, Gypsum Association, MD [M] Ajay V. Prasad, Hughes Associates, Inc., MD [SE] (Alt. to R. A. Wessel) (Alt. to J. J. Beitel) David L. Hall, Air Products and Controls Inc., MI [M] Mark Terzigni, Sheet Metal & Air Conditioning (Alt. to T. P. Hammerberg) Contractors Natl. Assn., VA [IM] Amando Lyndyll Hisole, ccrd partners, TX [SE] (Alt. to E. P. Howard, III) (Alt. to R. W. Tucker) Frank Wang, Aon Fire Protection Engineering, CA [I] Charles Joyce, The RJA Group, Inc., NY [SE] (Voting Alt. to AON Rep.) (Alt. to T. M. Dusza) Robert J. Wills, American Iron and Steel Institute, Ralph A. Koerber, ATCO Rubber Products, Inc., TX [M] AL [M] (Alt. to M. A. Koerber) (Alt. to R. E. Loyd)

Allan Fraser, NFPA Staff Liaison

This list represents the membership at the time the Committee was balloted on the final text of this edition. Since that time, changes in the membership may have occurred. A key to classifications is found at the back of the document. NOTE: Membership on a committee shall not in and of itself constitute an endorsement of the Association or any document developed by the committee on which the member serves. Committee Scope: This Committee shall have primary responsibility for documents on the construction, installation, operation, and maintenance of systems for air conditioning, warm air heating, and ventilating including filters, ducts, and related equipment to protect life and property from fire, smoke, and gases resulting from fire or from conditions having manifestations similar to fire.

2015 Edition CONTENTS 90A–3

Contents

Chapter 1 Administration ...... 90A–4 Chapter 5 Integration of a Ventilation and 1.1 Scope ...... 90A–4 Air-Conditioning System(s) with Building Construction ...... 90A–14 1.2 Purpose ...... 90A–4 5.1 Air-Handling Equipment Rooms ...... 90A–14 1.3 Application ...... 90A–4 5.2 Building Construction ...... 90A–14 1.4 Retroactivity ...... 90A–4 5.3 Penetrations — Protection of Openings .... 90A–14 1.5 Equivalency ...... 90A–4 5.4 Fire Dampers, Smoke Dampers, and Ceiling Dampers ...... 90A–15 Chapter 2 Referenced Publications ...... 90A–4 2.1 General ...... 90A–4 Chapter 6 Controls ...... 90A–16 6.1 Wiring 2.2 NFPA Publications ...... 90A–4 ...... 90A–16 6.2 Manual Control ...... 90A–16 2.3 Other Publications ...... 90A–4 6.3 Smoke Dampers ...... 90A–16 2.4 References for Extracts in Mandatory 6.4 Smoke Detection for Automatic Control ... 90A–17 Sections ...... 90A–5 Chapter 7 Acceptance Testing ...... 90A–17 Chapter 3 Definitions ...... 90A–5 7.1 General ...... 90A–17 3.1 General ...... 90A–5 7.2 Fire Dampers, Smoke Dampers, and 3.2 NFPA Official Definitions ...... 90A–5 Ceiling Dampers ...... 90A–17 3.3 General Definitions ...... 90A–6 7.3 Controls and Operating Systems ...... 90A–17 Annex A Explanatory Material ...... 90A–17 Chapter 4 HVAC Systems ...... 90A–7 4.1 General Requirements for Equipment ...... 90A–7 Annex B Maintenance ...... 90A–21 4.2 System Components ...... 90A–7 Annex C Informational References ...... 90A–22 4.3 Air Distribution ...... 90A–8 4.4 Materials ...... 90A–13 Index ...... 90A–24

2015 Edition 90A–4 INSTALLATION OF AIR-CONDITIONING AND VENTILATING SYSTEMS

NFPA 90A (2)*Buildings of Types III, IV, and V construction over three stories in height, regardless of volume Standard for the (3)*Buildings and spaces not covered by other applicable NFPA standards Installation of Air-Conditioning and (4)*Occupants or processes not covered by other applicable Ventilating Systems NFPA standards L 1.4 Retroactivity. The provisions of this standard shall not be 2015 Edition intended to be applied retroactively. Where a system is being altered, extended, or renovated, the requirements of this stan- IMPORTANT NOTE: This NFPA document is made available for dard shall apply only to the work being undertaken. use subject to important notices and legal disclaimers. These notices L 1.5 Equivalency. Nothing in this standard shall be intended to and disclaimers appear in all publications containing this document and may be found under the heading “Important Notices and Dis- prevent the use of new methods or devices, provided that suf- claimers Concerning NFPA Documents.” They can also be obtained ficient technical data are submitted to the authority having on request from NFPA or viewed at www.nfpa.org/disclaimers. jurisdiction to demonstrate that the proposed method or device is equivalent in quality, strength, durability, and safety to NOTICE: An asterisk (*) following the number or letter designating a paragraph indicates that explanatory material that prescribed by this standard. on the paragraph can be found in Annex A. A reference in brackets [ ] following a section or paragraph indicates material that has been extracted from another NFPA L Chapter 2 Referenced Publications document. As an aid to the user, the complete title and edition of the source documents for extracts in mandatory sections of 2.1 General. The documents or portions thereof listed in this the document are given in Chapter 2 and those for extracts in chapter are referenced within this standard and shall be con- informational sections are given in Annex C. Extracted text sidered part of the requirements of this document. may be edited for consistency and style and may include the revision of internal paragraph references and other refer- 2.2 NFPA Publications. National Fire Protection Association, ences as appropriate. Requests for interpretations or revisions 1 Batterymarch Park, Quincy, MA 02169-7471. of extracted text shall be sent to the technical committee re- NFPA 30, Flammable and Combustible Liquids Code, 2015 edi- sponsible for the source document. tion. Information on referenced publications can be found in NFPA 31, Standard for the Installation of Oil-Burning Equip- Chapter 2 and Annex C. ment, 2011 edition. NFPA 54, National Fuel Gas Code, 2015 edition. NFPA 70®, National Electrical Code®, 2014 edition. ® L Chapter 1 Administration NFPA 72 , National Fire Alarm and Signaling Code, 2013 edition. L 1.1* Scope. This standard shall cover construction, installa- NFPA 75, Standard for the Fire Protection of Information Technol- tion, operation, and maintenance of systems for air condition- ogy Equipment, 2013 edition. ing and ventilating, including filters, ducts, and related equip- NFPA 80, Standard for Fire Doors and Other Opening Protectives, ment, to protect life and property from fire, smoke, and gases 2013 edition. resulting from fire or from conditions having manifestations NFPA 101®, Life Safety Code®, 2015 edition. similar to fire. NFPA 105, Standard for Smoke Door Assemblies and Other Open- ing Protectives, 2013 edition. L 1.2 Purpose. This standard shall prescribe minimum requirements for safety to life and property from fire. These require- NFPA 259, Standard Test Method for Potential Heat of Building ments shall be intended to accomplish the following: Materials, 2013 edition. NFPA 262, Standard Method of Test for Flame Travel and Smoke (1) Restrict the spread of smoke through air duct systems of Wires and Cables for Use in Air-Handling Spaces, 2011 edition. within a building or into a building from the outside NFPA 275, Standard Method of Fire Tests for the Evaluation of (2) Restrict the spread of fire through air duct systems from Thermal Barriers, 2013 edition. the area of fire origin, whether located within the build- NFPA 286, Standard Methods of Fire Tests for Evaluating Contri- ing or outside bution of Wall and Ceiling Interior Finish to Room Fire Growth, 2011 (3) Maintain the fire-resistive integrity of building compo- edition. nents and elements such as floors, partitions, roofs, walls, NFPA 5000®, Building Construction and Safety Code®, 2015 and floor– or roof–ceiling assemblies affected by the installation of air duct systems edition. (4) Minimize the ignition sources and combustibility of the 2.3 Other Publications. elements of the air duct systems (5) Permit the air duct systems in a building to be used for the 2.3.1 ASHRAE Publications. American Society of Heating, additional purpose of emergency smoke control Refrigerating and Air-Conditioning Engineers, Inc., 1791 Tul- lie Circle, NE, Atlanta, GA 30329-2305. L 1.3 Application. This standard shall apply to all systems for the movement of environmental air in structures that serve ANSI/ASHRAE 15, Safety Code for Mechanical Refrigeration, the following: 2001. (1)*Spaces over 708 m3 (25,000 ft3) in volume ASHRAE Handbook — HVAC Systems and Equipment, 2000.

2015 Edition DEFINITIONS 90A–5

2.3.2 ASTM International Publications. ASTM Interna- ANSI/UL 867, Standard for Safety Electrostatic Air Cleaners, tional, 100 Barr Harbor Drive, P.O. Box C700, West Consho- 2011, Revised 2013. hocken, PA 19428-2959. ANSI/UL 900, Standard for Safety Air Filter Units, 2004, ASTM C 411, Standard Test Method for Hot-Surface Performance Revised 2012. of High-Temperature Thermal Insulation, 2011. ANSI/UL 1820, Standard for Safety Fire Test of Pneumatic Tub- ASTM D 93, Standard Test Methods for Flashpoint by Pensky- ing for Flame and Smoke Characteristics, 2004, Revised 2013. Martens Closed Cup Tester, 2012. ANSI/UL 1887, Standard for Safety Fire Test of Plastic Sprinkler ASTM E 84, Standard Test Method for Surface Burning Charac- Pipe for Visible Flame and Smoke Characteristics, 2004, Revised teristics of Building Materials, 2013a. 2013. ASTM E 119, Standard Test Methods for Fire Tests of Building ANSI/UL 1995, Standard for Safety Heating and Cooling Construction and Materials, 2012a. Equipment, 2011. ASTM E 136, Standard Test Method for Behavior of Materials in ANSI/UL 2024, Standard for Signaling, Optical Fiber and Com- a Vertical Tube Furnace at 750°C, 2012. munications Raceways and Cable Routing Assemblies, 2011. ASTM E 2231, Standard Practice for Specimen Preparation and ANSI/UL 2043, Standard for Safety Fire Test for Heat and Visible Mounting of Pipe and Duct Insulation Materials to Assess Surface Smoke Release for Discrete Products and Their Accessories Installed in Burning Characteristics, 2009. Air-Handling Spaces, 2008. ASTM E 2652, Standard Test Method for Behavior of Materials UL 2518, Outline of Investigation for Air Dispersion System Ma- in a Tube Furnace with a Cone- Shaped Airflow Stabilizer, at 750°C, terials, 2005. 2012. 2.3.7 Other Publications. Merriam-Webster’s Collegiate Dictio- nary, 11th edition, Merriam-Webster, Inc., Springfield, MA, 2.3.3 GA Publications. Gypsum Association, 6525 Belcrest 2003. Road, Suite 480, Hyattsville, MD 20782. 2.4 References for Extracts in Mandatory Sections. GA 600, Fire Resistance Design Manual, 19th edition, 2009. NFPA 90B, Standard for the Installation of Warm Air Heating 2.3.4 NAIMA Publications. North American Insulation and Air-Conditioning Systems, 2015 edition. ® ® Manufacturers Association, 44 Canal Center Plaza, Suite 310, NFPA 101 , Life Safety Code , 2015 edition Alexandria, VA 22314. NFPA 211, Standard for Chimneys, Fireplaces, Vents, and Solid Fuel–Burning Appliances, 2013 edition. Fibrous Glass Duct Construction Standards, 5th edition, 2002. NFPA 5000®, Building Construction and Safety Code®, 2015 edition. 2.3.5 SMACNA Publications. Sheet Metal and Air Condition- ing Contractors’ National Association, 4201 Lafayette Center Drive, Chantilly, VA 20151-1209. Fibrous Glass Duct Construction Standards, 7th edition, 2003. L Chapter 3 Definitions HVAC Air Duct Leakage Test Manual, 1st edition, 1985. L 3.1 General. The definitions contained in this chapter shall apply to the terms used in this standard. Where terms are not HVAC Duct Construction Standards — Metal and Flexible, defined in this chapter or within another chapter, they shall 3rd edition, 2005. be defined using their ordinarily accepted meanings within 2.3.6 UL Publications. Underwriters Laboratories Inc., the context in which they are used. Merriam-Webster’s Collegiate 333 Pfingsten Road, Northbrook, IL 60062-2096. Dictionary, 11th edition, shall be the source for the ordinarily accepted meaning. ANSI/UL 181, Standard for Safety Factory-Made Air Ducts and Air Connectors, 2013. L 3.2 NFPA Official Definitions. ANSI/UL 181A, Standard for Safety Closure Systems for Use with 3.2.1* Approved. Acceptable to the authority having jurisdic- Rigid Air Ducts, 2013. tion. ANSI/UL 181B, Standard for Safety Closure Systems for Use with L 3.2.2* Authority Having Jurisdiction (AHJ). An organization, Flexible Air Ducts and Air Connectors, 2013. office, or individual responsible for enforcing the requirements of a code or standard, or for approving equipment, ANSI/UL 263, Standard for Fire Tests of Building Construction materials, an installation, or a procedure. and Materials, 2011. L 3.2.3* Listed. Equipment, materials, or services included in a ANSI/UL 555, Standard for Safety Fire Dampers, 2006, Revised list published by an organization that is acceptable to the au- 2012. thority having jurisdiction and concerned with evaluation of ANSI/UL 555C, Standard for Safety Ceiling Dampers, 2006, products or services, that maintains periodic inspection of Revised 2010. production of listed equipment or materials or periodic evaluation of services, and whose listing states that either the equip- ANSI/UL 555S, Standard for Safety Smoke Dampers, 1999, ment, material, or service meets appropriate designated stan- Revised 2012. dards or has been tested and found suitable for a specified purpose. ANSI/UL 723, Standard for Test for Surface Burning Character- istics of Building Materials, 2008, Revised 2013. 3.2.4 Shall. Indicates a mandatory requirement.

2015 Edition 90A–6 INSTALLATION OF AIR-CONDITIONING AND VENTILATING SYSTEMS

3.2.5 Should. Indicates a recommendation or that which is roof-ceiling assembly to automatically limit the radiative advised but not required. heat transfer through an air inlet/outlet opening. 3.2.6 Standard. A document, the main text of which contains 3.3.14.2 Combination Fire and Smoke Damper. A device that only mandatory provisions using the word “shall” to indicate meets both fire damper and smoke damper requirements. requirements and which is in a form generally suitable for L mandatory reference by another standard or code or for adop- 3.3.14.3* Fire Damper. A device installed in an air distribution into law. Nonmandatory provisions are not to be consid- tion system and designed to close automatically upon de- ered a part of the requirements of a standard and shall be tection of heat, to interrupt migratory airflow, and to re- located in an appendix, annex, footnote, informational note, strict the passage of flame. or other means as permitted in the Manual of Style for NFPA 3.3.14.4* Smoke Damper. A device within an air- Technical Committee Documents. distribution system to control the movement of smoke. L 3.3 General Definitions. [5000, 2015] 3.3.1 Accessible. Capable of being removed or exposed with- 3.3.15 Environmental Air. Air that is supplied, returned, recir- out damaging the building structure or finish, or not perma- culated, or exhausted from spaces for the purpose of modify- nently closed in by the structure or finish of the building. ing the existing atmosphere within the building. 3.3.2 Air Cleaner. A device used to reduce or remove air- 3.3.16 Fan. A blower or exhauster assembly comprising borne solids from heating, ventilating, and air-conditioning blades or runners and housings or casings. [211, 2013] systems by electrostatic means. 3.3.17* Fire Resistance Rating. The time, in minutes or 3.3.3* Air Connector. A conduit for transferring air between hours, that materials or assemblies have withstood a fire an air duct or plenum and an air terminal unit or an air inlet exposure as established in accordance with the test proce- or air outlet. dures of ASTM E 119, Standard Test Methods for Fire Tests of L 3.3.4 Air Distribution System. A continuous passageway for Building Construction and Materials, or ANSI/UL 263, Stan- the transmission of air that, in addition to air ducts, can in- dard for Fire Tests of Building Construction and Materials. clude air connectors, air duct fittings, dampers, plenums, fans, 3.3.18 Fire Wall. A wall separating buildings or subdividing a and accessory air-handling equipment but that does not in- building to prevent the spread of fire and having a fire resis- clude conditioned spaces. tance rating and structural stability. 3.3.5 Air Duct. A conduit or passageway for conveying air to 3.3.19* Flame Spread Index. A comparative measure ex- or from heating, cooling, air-conditioning, or ventilating pressed as a dimensionless number derived from visual mea- equipment, but not including the plenum. surements or the spread of flame versus time in ASTM E 84, 3.3.6 Air Duct Covering. A material such as an adhesive, insu- Standard Test Method for Surface Burning Characteristics of Build- lation, banding, a coating(s), film, or a jacket used to cover the ing Materials, or ANSI/UL 723, Standard for Test for Surface Burn- outside surface of an air duct, fan casing, or duct plenum. ing Characteristics of Building Materials. 3.3.7 Air Duct Lining. A material such as an adhesive, insula- 3.3.20 Foam Plastic Insulation. A cellular plastic, used for tion, a coating(s), or film used to line the inside surface of an thermal insulating or acoustical applications, having a density air duct, fan casing, or duct plenum. of 20 lb/ft3 (320 kg/m3) or less, containing open or closed cells, and formed by a foaming agent. [5000, 2015] 3.3.8 Air Filter. A device used to reduce or remove airborne solids from heating, ventilating, and air-conditioning systems. L 3.3.21* Limited-Combustible (Material). See 4.4.2. [90B, 2015] 3.3.22* Noncombustible Material. See 4.4.1. 3.3.9* Air Inlet. Any opening through which air is removed L from a space and returned to an air distribution system. 3.3.23* Plenum. A compartment or chamber to which one or more air ducts are connected and that forms part of the air 3.3.10* Air Outlet. Any opening through which air is deliv- distribution system. ered to a space from an air distribution system. 3.3.23.1 Air-Handling Unit Room Plenum. An individual 3.3.11 Air Terminal Unit. An appliance receiving, condition- room containing an air-handling unit(s) used to gather air ing, and delivering air supplied through an air distribution from various sources and combine the air within the room system. before returning it to the air-handling unit. 3.3.12 Air Transfer Opening. An opening designed to allow 3.3.23.2 Apparatus Casing Plenum. A sheet metal construc- the movement of environmental air between two contiguous tion attached directly to a fan enclosure, fan coil unit, air- spaces. handling unit, or furnace bonnet for the purpose of con- 3.3.13 Continued Progressive Combustion. A flame front pro- necting distribution ducts. gressing more than 3.2 m (10.5 ft) beyond the centerline of 3.3.23.3 Ceiling Cavity Plenum. The space between the top the burners during a test in accordance with ASTM E 84, Stan- of the finished ceiling and the underside of the floor above dard Test Method for Surface Burning Characteristics of Building or the roof and used to supply air to the occupied area or to Materials, or ANSI/UL 723, Standard for Test for Surface Burning return air to or exhaust air from the occupied area. Characteristics of Building Materials. 3.3.23.4 Raised Floor Plenum. The space between the top 3.3.14 Damper. of the finished floor and the underside of a raised floor and 3.3.14.1* Ceiling Damper. A listed device installed in a ceil- used to supply air to the occupied area or to return air to or ing membrane of a fire resistance–rated floor-ceiling or exhaust air from the occupied area.

2015 Edition HVAC SYSTEMS 90A–7

3.3.24 Smoke. The airborne solid and liquid particulates and 4.2.2.2* Air filters shall comply with ANSI/UL 900, Standard gases evolved when a material undergoes pyrolysis or combus- for Safety Air Filter Units. tion, together with the quantity of air that is entrained or otherwise mixed into the mass. 4.2.2.3 Liquid adhesive coatings used on air filters shall have a minimum flash point of 163°C (325°F) as determined by 3.3.25* Smoke Barrier. A continuous membrane, or a mem- ASTM D 93, Standard Test Methods for Flashpoint by Pensky- brane with discontinuities created by protected openings, Martens Closed Cup Tester. where such membrane is designed and constructed to restrict the movement of smoke. [5000, 2015] 4.2.2.4 Where air filters are flushed with liquid adhesives, the system shall be arranged so that the air cleaner cannot be 3.3.26 Smoke Control. A system that utilizes fans to produce flushed while the fan is in operation. pressure differences so as to manage smoke movement. 4.2.2.5 Combustible adhesive coatings shall be stored in ac- 3.3.27* Smoke Detector. A device that senses visible or invis- cordance with NFPA 30, Flammable and Combustible Liquids ible particles of combustion. Code. 3.3.28* Smoke Developed Index. A comparative measure ex- 4.2.3 Fans. pressed as a dimensionless number, derived from measure- ments of smoke obstruction versus time in ASTM E 84 Stan- 4.2.3.1 Installation. dard Test Method for Surface Burning Characteristics of Building 4.2.3.1.1 Fans shall be installed in accordance with the appli- Materials, or ANSI/UL 723, Standard for Test for Surface Burning cable NFPA standards and the manufacturer’s instructions. Characteristics of Building Materials . 4.2.3.1.2 Fans shall be approved for the specific installation. 4.2.3.2 Access. Fans shall be located, arranged, and installed L Chapter 4 HVAC Systems to afford access for inspection and maintenance. 4.2.3.3 Exposed Inlets. Exposed fan inlets shall be protected 4.1 General Requirements for Equipment. with metal screens to prevent the entry of paper, trash, and 4.1.1 Access. Equipment shall be arranged to afford access for foreign materials. inspection, maintenance, and repair. 4.2.4 Air-Cooling and Heating Equipment. 4.1.2 Equipment shall be selected and installed based on its 4.2.4.1 Installation. application with respect to the manufacturer’s installation instructions and listing, as applicable. 4.2.4.1.1 Heating and cooling equipment shall be installed in accordance with the applicable NFPAstandards and the manu- 4.1.3 Protection. facturer’s instructions. 4.1.3.1 Equipment shall be guarded for personnel protec- 4.2.4.1.2 The equipment shall be approved for the specific tion. installation. (See 4.3.3.1.) 4.1.3.2 Equipment shall be guarded against the intake of for- 4.2.4.2 Materials. Materials used in the manufacturing of fan eign matter into the system. coil units, self-contained air-conditioning units, furnaces, heat pumps, humidifiers, and all similar equipment shall meet the 4.1.4 Electrical wiring and equipment shall be installed in requirements of 4.3.3.1 and 4.3.3.2 unless otherwise specified accordance with NFPA 70, National Electrical Code. in 4.2.4.2.1 or 4.2.4.2.2. 4.1.5 Air-handling equipment rooms shall meet the require- 4.2.4.2.1 The requirements of 4.3.3.1 and 4.3.3.2 shall not apply ments of Section 5.1. to equipment tested and listed in accordance with ANSI/UL 4.2 System Components. 1995, Standard for Safety Heating and Cooling Equipment. 4.2.1 Outside Air Intakes. 4.2.4.2.2 Unlisted solar energy air distribution system components shall be accompanied by supportive information dem- 4.2.1.1 Outside air intakes shall be protected by screens of onstrating that the components have flame spread and smoke corrosion-resistant material not larger than 12.7 mm (0.5 in.) developed indexes that are not in excess of those of the air mesh. duct system permitted by this standard. 4.2.1.2* Outside air intakes shall be located so as to minimize 4.2.4.3 Mechanical Cooling. the introduction of fire or smoke into the building. 4.2.4.3.1 Mechanical refrigeration used with air duct systems 4.2.1.2.1 Outside air intakes shall be equipped with an ap- shall be installed in accordance with recognized safety practices. proved fire and/or smoke damper where not located to meet the requirements of 4.2.1.2. (See Section 6.3 for smoke damper 4.2.4.3.2 Installations conforming to ANSI/ASHRAE 15, operation to restrict the intake of smoke.) Safety Code for Mechanical Refrigeration, shall be considered to be in compliance with the requirement in 4.2.4.3.1. 4.2.2 Air Cleaners and Air Filters. 4.2.4.4 Furnaces. 4.2.2.1 Electrostatic air cleaners shall be listed in accordance with ANSI/UL 867, Standard for Safety Electrostatic Air Cleaners. 4.2.4.4.1 Oil-burning heating furnaces combined with cooling units in the same air duct system shall be installed in accor- 4.2.2.1.1 Electrostatic air cleaners shall be installed in con- dance with NFPA 31, Standard for the Installation of Oil-Burning formance with the conditions of the manufacturer’s listing. Equipment.

2015 Edition 90A–8 INSTALLATION OF AIR-CONDITIONING AND VENTILATING SYSTEMS

4.2.4.4.2 Gas-burning heating furnaces combined with cool- 4.3.1.6 Where no standard exists for the construction of air ing units in the same air duct system shall be installed in accor- ducts, the ducts shall be constructed to withstand both the dance with NFPA 54, National Fuel Gas Code. maximum positive and the maximum negative pressures of the system at fan shutoff. 4.2.4.5 Duct Heaters. 4.3.1.7 A duct enclosure used for the multiple distribution or 4.2.4.5.1 Where electrical resistance or fuel-burning heaters gathering of ducts or connectors shall be constructed of mate- are installed in air ducts, the air duct coverings and their in- rials and methods specified in 4.3.1. stallation shall comply with the provisions of 4.3.5.3. 4.3.1.7.1 Electrical wires and cables and optical fiber cables 4.2.4.5.2 The installation of electrical duct heaters shall com- within a duct enclosure shall comply with 4.3.4. ply with the provisions of NFPA 70, National Electrical Code, Ar- ticle 424, Part VI, “Duct Heaters.” 4.3.1.8 Air Dispersion Systems. Air dispersion systems shall meet the following criteria: 4.2.4.6 Evaporative Coolers. Combustible evaporation media shall not be used unless they meet the requirements of 4.2.2.2. (1) They shall only be installed in entirely exposed locations. (2) They shall always operate under positive pressure. 4.2.4.7 Heat Recovery Equipment. Equipment not covered by (3) They shall not penetrate fire resistance–rated construc- other provisions of this standard and used for heat transfer or tion. air movement shall be constructed so that all material in the (4) They shall not pass through fire resistance–rated con- air path meets the requirements of Section 4.2. struction. 4.3* Air Distribution. (5) They shall be listed and labeled in accordance with UL 2518, Outline of Investigation for Air Dispersion System 4.3.1 Air Ducts. Materials. 4.3.1.1 Air ducts shall be constructed of iron, steel, alumi- 4.3.2 Air Connectors. num, copper, concrete, masonry, or clay tile, except as otherwise permitted in 4.3.1.2 or 4.3.1.3. 4.3.2.1 Air connectors are limited-use, flexible air ducts that shall not be required to conform to the provisions for air ducts 4.3.1.2 Class 0 or Class 1 rigid or flexible air ducts tested in where they meet the requirements of 4.3.2.1.1 through accordance with ANSI/UL 181, Standard for Safety Factory-Made 4.3.2.1.5. Air Ducts and Air Connectors, and installed in conformance with the conditions of listing shall be permitted to be used for ducts 4.3.2.1.1 Air connectors shall conform to the requirements where air temperature in the ducts does not exceed 121°C for Class 0 or Class 1 connectors when tested in accordance (250°F) or where used as vertical ducts serving not more than with ANSI/UL 181, Standard for Safety Factory-Made Air Ducts two adjacent stories in height. and Air Connectors. 4.3.1.3 Gypsum Board Air Ducts. 4.3.2.1.2 Class 0 or Class 1 air connectors shall not be used for ducts containing air at temperatures in excess of 121°C 4.3.1.3.1 Gypsum board having a flame spread index not ex- (250°F). ceeding 25 without evidence of continued progressive combustion and a smoke developed index not exceeding 50 when tested 4.3.2.1.3 Air connector runs shall not exceed 4.27 m (14 ft) in accordance with ASTM E 84, Standard Test Method for Surface in length. Burning Characteristics of Building Materials, or ANSI/UL 723, Stan- 4.3.2.1.4 Air connectors shall not pass through any wall, par- dard for Test for Surface Burning Characteristics of Building Materials, tition, or enclosure of a vertical shaft that is required to have a shall be permitted to be used for negative pressure exhaust and fire resistance rating of 1 hour or more. return ducts where the temperature of the conveyed air does not exceed 52°C (125°F) in normal service. 4.3.2.1.5 Air connectors shall not pass through floors. 4.3.1.3.2 The air temperature limits of 4.3.1.3.1 shall not ap- 4.3.2.2 Vibration isolation connectors in duct systems shall be ply where gypsum board material is used for emergency smoke made of materials having a maximum flame spread index of exhaust air ducts. 25 and a maximum smoke developed index of 50. 4.3.1.4 All air duct materials shall be suitable for continuous 4.3.2.3 Wiring shall not be installed in air connectors. exposure to the temperature and humidity conditions of the L 4.3.3 Supplementary Materials for Air Distribution Systems. environmental air in the air duct. 4.3.3.1* Pipe and duct insulation and coverings, duct linings, 4.3.1.5 The materials, thickness, construction, and installa- vapor retarder facings, adhesives, fasteners, tapes, and supple- tion of ducts shall provide structural strength and durability in mentary materials added to air ducts, plenums, panels, and conformance with recognized good practice. duct silencers used in duct systems, unless otherwise provided 4.3.1.5.1 Air ducts shall be considered to be in compliance for in 4.3.3.1.1 or 4.3.3.1.2, shall have, in the form in which with 4.3.1.5 where constructed and installed in accordance they are used, a maximum flame spread index of 25 without with the ASHRAE Handbook — HVAC Systems and Equipment and evidence of continued progressive combustion and a maxi- with one of the following as applicable: mum smoke developed index of 50 when tested in accordance with ASTM E 84, Standard Test Method for Surface Burning Char- (1) NAIMA Fibrous Glass Duct Construction Standards acteristics of Building Materials, or with ANSI/UL 723, Standard (2) SMACNA Fibrous Glass Duct Construction Standards for Test for Surface Burning Characteristics of Building Materials. (3) SMACNA HVAC Duct Construction Standards — Metal and Pipe and duct insulation and coverings, duct linings and their Flexible adhesives, and tapes shall use the specimen preparation and (4) SMACNA HVAC Air Duct Leakage Test Manual mounting procedures of ASTM E 2231, Standard Practice for

2015 Edition HVAC SYSTEMS 90A–9

Specimen Preparation and Mounting of Pipe and Duct Insulation that meets the requirements of 4.3.11.2.6.2 to connect to Materials to Assess Surface Burning Characteristics. equipment. 4.3.3.1.1 The flame spread index and smoke developed in- 4.3.5 Air Duct Access and Inspection. dex requirements of 4.3.3.1 shall not apply to air duct weath- L 4.3.5.1 A service opening shall be provided in air ducts erproof coverings where they are located entirely outside a adjacent to each fire damper, smoke damper, combination building, do not penetrate a wall or roof, and do not create an fire/smoke damper, and any smoke detectors that need ac- exposure hazard. cess for installation, cleaning, maintenance, inspection, 4.3.3.1.2 Smoke detectors required by 6.4.4 shall not be re- and testing. quired to meet flame spread index or smoke developed index 4.3.5.1.1 The opening shall be large enough to permit main- requirements. tenance and resetting of the device. 4.3.3.2 Closure systems for use with rigid and flexible air 4.3.5.2 Service openings shall be identified with letters hav- ducts tested in accordance with ANSI/UL 181, Standard for ing a minimum height of 12.7 mm (1⁄2 in.) to indicate the Safety Factory-Made Air Ducts and Air Connectors, shall have been location of the fire protection device(s) within. tested, listed, and used in accordance with the conditions of 4.3.5.3 Horizontal air ducts and plenums shall be provided their listings, in accordance with one of the following: with service openings to facilitate the removal of accumula- (1) ANSI/UL 181A, Standard for Safety Closure Systems for Use tions of dust and combustible materials. with Rigid Air Ducts 4.3.5.3.1 Service openings shall be located at approximately (2) ANSI/UL 181B, Standard for Safety Closure Systems for Use 6.1 m (20 ft) intervals along the air duct and at the base of with Flexible Air Ducts and Air Connectors each vertical riser, unless otherwise permitted in 4.3.5.3.2 4.3.3.3 Coverings and linings for air ducts, pipes, plenums, through 4.3.5.3.4. and panels, including all pipe and duct insulation materials, 4.3.5.3.2 Removable air outlet or air inlet devices of adequate shall not flame, glow, smolder, or smoke when tested in accor- size shall be permitted in lieu of service openings. dance with ASTM C 411, Standard Test Method for Hot-Surface 4.3.5.3.3 Service openings shall not be required in supply Performance of High-Temperature Thermal Insulation, at the tem- ducts where the supply air has previously passed through an perature to which they are exposed in service. In no case shall air filter, an air cleaner, or a water spray. the test temperature be below 121°C (250°F). 4.3.5.3.4 Service openings shall not be required where all the 4.3.3.4 Air duct coverings shall not extend through walls or following conditions exist: floors that are required to be fire stopped or required to have a fire resistance rating, unless such coverings meet the re- (1) The occupancy has no process that produces combustible quirements of NFPA 80, Standard for Fire Doors and Other Open- material such as dust, lint, or greasy vapors. Such occu- ing Protectives. pancies include banks, office buildings, churches, hotels, and health care facilities (but not kitchens, laundries, and 4.3.3.5* Air duct linings shall be interrupted at fire dampers to manufacturing portions of such facilities). prevent interference with the operation of devices. (2) The air inlets are at least 2.13 m (7 ft) above the floor or are protected by corrosion-resistant metal screens of at 4.3.3.6 Air duct coverings shall not be installed so as to con- least 14 mesh [1.8 mm (0.07 in.)] that are installed at the ceal or prevent the use of any service opening. inlets so that they cannot draw papers, refuse, or other 4.3.3.7* Wall or ceiling finish in plenums shall comply with combustible solids into the return air duct. 4.3.11.6. (3) The minimum design velocity in the return duct for the particular occupancy is 5.08 m/sec (1000 ft/min). 4.3.4 Materials for Operation and Control of the Air Distribu- tion System. 4.3.5.4 Inspection windows shall be permitted in air ducts, provided they are glazed with wired or fire protection–rated 4.3.4.1* Wiring shall not be installed in air ducts, except as glass. permitted in 4.3.4.2 through 4.3.4.4. 4.3.5.5 Openings in walls or ceilings shall be provided so that 4.3.4.2 Wiring shall be permitted to be installed in air ducts service openings in air ducts are accessible for maintenance only if the wiring is directly associated with the air distribution and inspection needs. system and does not exceed 1.22 m (4 ft). 4.3.5.6 Where a service opening is necessary in an air duct 4.3.4.3 Wiring permitted by 4.3.4.2 shall be as short as practi- located above the ceiling of a floor-ceiling or a roof-ceiling cable. assembly that has been tested and assigned a fire resistance rating in accordance with ASTM E 119, Standard Test Methods 4.3.4.4* Electrical wires and cables and optical fiber cables for Fire Tests of Building Construction and Materials, or ANSI/UL shall consist of wires or cables listed as having a maximum 263, Standard for Fire Tests of Building Construction and Materials, peak optical density of 0.50 or less, an average optical density access shall be provided in the ceiling. of 0.15 or less, and a maximum flame spread distance of 1.5 m (5 ft) or less when tested in accordance with NFPA 262, Stan- 4.3.5.7 The service opening shall be designed and installed dard Method of Test for Flame Travel and Smoke of Wires and Cables so that it does not reduce the fire resistance rating of the as- for Use in Air-Handling Spaces, or shall be installed in metal race- sembly. ways without an overall nonmetallic covering or metal 4.3.6 Air Duct Integrity. sheathed cable without an overall nonmetallic covering. 4.3.6.1 Air ducts shall be located where they are not subject 4.3.4.5 Nonmetallic pneumatic tubing for control systems to damage or rupture, or they shall be protected to maintain shall be permitted to have up to 457.2 mm (18 in.) of tubing their integrity.

2015 Edition 90A–10 INSTALLATION OF AIR-CONDITIONING AND VENTILATING SYSTEMS

4.3.6.2 Where an air duct is located outdoors, the air duct, having openings through which a 12.7 mm (1⁄2 in.) sphere together with its covering or lining, shall be protected from cannot pass. harmful elements. 4.3.9 Fire Dampers. 4.3.6.3 Where electrical, fossil fuel, or solar energy collection heat sources are installed in air ducts, the installation shall 4.3.9.1 Approved fire dampers shall be provided as required avoid the creation of a fire hazard. in Chapter 5. 4.3.6.3.1 For air ducts rated as Class 1 in accordance with 4.3.9.2 Approved fire dampers shall be installed in conform- ANSI/UL 181, Standard for Safety Factory-Made Air Ducts and Air ance with the conditions of their listings. Connectors, air duct coverings and linings shall be interrupted 4.3.10 Smoke Dampers. at the immediate area of operation of such heat sources in 4.3.5.3 in order to meet the clearances specified as a condition 4.3.10.1 Approved smoke dampers shall be provided as re- of the equipment listing, unless otherwise permitted in quired in Chapter 5. 4.3.5.3.2 or 4.3.5.3.3. 4.3.10.1.1 Approved smoke dampers shall be installed in con- 4.3.6.3.2 Appliances listed for zero clearance from combus- formance with the conditions of their listings. tibles shall be permitted to be installed in accordance with the 4.3.10.2 Smoke dampers shall be installed in systems with a conditions of their listings. capacity greater than 7080 L/sec (15,000 ft3/min) to isolate 4.3.6.3.3 Insulation specifically suited for the maximum tem- the air-handling equipment, including filters, from the re- perature that reasonably can be anticipated on the duct sur- mainder of the system on both the building supply side and face shall be permitted to be installed at the immediate area of the return side, in order to restrict the circulation of smoke, operation of such appliances. unless specifically exempted by 4.3.10.2.1 or 4.3.10.2.2. 4.3.7 Air Outlets. 4.3.10.2.1 Air-handling units located on the floor they serve and serving only that floor shall be exempt from the require- 4.3.7.1 General. Air supplied to any space shall not contain ments of 4.3.10.2. flammable vapors, flyings, or dust in quantities and concentrations that would introduce a hazardous condition. 4.3.10.2.2 Air-handling units located on the roof and serving only the floor immediately below the roof shall be exempt 4.3.7.2 Construction of Air Outlets. Air outlets shall be con- from the requirements of 4.3.10.2. structed of noncombustible material or of a material that has a maximum flame spread index of 25 and a maximum smoke 4.3.11 Plenums. developed index of 50 when tested in accordance with ASTM 4.3.11.1 Storage. E 84, Standard Test Method for Surface Burning Characteristics of Building Materials, or ANSI/UL 723, Standard for Test for Surface 4.3.11.1.1 Plenums shall not be used for occupancy or stor- Burning Characteristics of Building Materials. age. 4.3.7.3 Location of Air Outlets. 4.3.11.1.2 Accessible abandoned material shall be deemed to be in storage and shall be removed. Where cables are identi- 4.3.7.3.1 Air outlets shall be located at least 76 mm (3 in.) fied for future use with a tag, the tag shall be of sufficient above the floor, unless provisions have been made to prevent durability to withstand the environment involved. dirt and dust accumulations from entering the system. 4.3.11.2 Ceiling Cavity Plenum. The space between the top of 4.3.7.3.2 Where located less than 2.13 m (7 ft) above the the finished ceiling and the underside of the floor or roof floor, outlet openings shall be protected by a grille or screen above shall be permitted to be used to supply air to the occu- 1 having openings through which a 12.7 mm ( ⁄2 in.) sphere pied area or to return or exhaust air from the occupied area, cannot pass. provided that the conditions in 4.3.11.2.1 through 4.3.11.2.7 4.3.8 Air Inlets — Return or Exhaust or Return and Exhaust. are met. 4.3.8.1 General. Air shall not be recirculated from any space 4.3.11.2.1 The integrity of the fire and smoke stopping for in which flammable vapors, flyings, or dust are present in penetrations shall be maintained. quantities and concentrations that would introduce a hazard- 4.3.11.2.2 Light diffusers, other than those made of metal or ous condition into the return air system. glass, used in air-handling light fixtures shall be listed and 4.3.8.2 Construction of Air Inlets. Air inlets shall be con- marked “Fixture Light Diffusers for Air-Handling Fixtures.” structed of noncombustible material or a material that has a 4.3.11.2.3 The temperature of air delivered to these plenums maximum flame spread index of 25 and a maximum smoke shall not exceed 121°C (250°F). developed index of 50 when tested in accordance with ASTM E 84, Standard Test Method for Surface Burning Characteristics of 4.3.11.2.4 Materials used in the construction of a ceiling ple- Building Materials, or ANSI/UL 723, Standard for Test for Surface num shall be noncombustible or shall be limited combustible Burning Characteristics of Building Materials. having a maximum smoke developed index of 50, except as permitted in 4.3.11.2.4.1 through 4.3.11.2.4.3, and shall be 4.3.8.3 Location of Air Inlets. suitable for continuous exposure to the temperature and hu- 4.3.8.3.1 Air inlets shall be located at least 76 mm (3 in.) midity conditions of the environmental air in the plenum. above the floor, unless provisions have been made to prevent 4.3.11.2.4.1 Materials used in the construction of a plenum dirt and dust accumulations from entering the system. space between the ceiling and roof (or floor) of other than the 4.3.8.3.2 Where located less than 2.13 m (7 ft) above the fire-resistive assemblies covered in 5.3.3 shall be permitted as floor, inlet openings shall be protected by a grille or screen specified in 4.3.11.2.4.2 and 4.3.11.2.4.3.

2015 Edition HVAC SYSTEMS 90A–11

4.3.11.2.4.2 The ceiling material shall have a flame spread with ANSI/UL 2043, Standard for Safety Fire Test for Heat and index of not more than 25 and a smoke developed index not Visible Smoke Release for Discrete Products and Their Accessories In- greater than 50. All surfaces, including those that would be stalled in Air-Handling Spaces. exposed by cutting through the material in any way, shall meet 4.3.11.2.6.6 Plastic piping and tubing used in plumbing sys- these requirements. tems shall be permitted to be used within a ceiling cavity ple- 4.3.11.2.4.3 The ceiling materials shall be supported by non- num if it exhibits a flame spread index of 25 or less and a combustible material. smoke developed index of 50 or less when tested in accordance with ASTM E 84, Standard Test Method for Surface Burning 4.3.11.2.5 Where the plenum is a part of a floor-ceiling or Characteristics of Building Materials, or ANSI/UL 723, Standard roof-ceiling assembly that has been tested or investigated and for Test for Surface Burning Characteristics of Building Materials, at assigned a fire resistance rating of 1 hour or more, the assem- full width of the tunnel and with no water or any other liquid bly shall meet the requirements of 5.3.3. in the pipe during the test. 4.3.11.2.6 Materials within a ceiling cavity plenum exposed to 4.3.11.2.6.7 Supplementary materials for air distribution sys- the airflow shall: tems shall be permitted provided they comply with the provi- (1) Be noncombustible, or sions of 4.3.3. (2) Exhibit a maximum flame spread index of 25 and a maxi- 4.3.11.2.6.8 Smoke detectors shall not be required to meet mum smoke developed index of 50 when tested in accor- the provisions of Section 4.3. dance with ASTM E 84, Standard Test Method for Surface Burning Characteristics of Building Materials, or with 4.3.11.2.6.9 Air ducts complying with 4.3.1.2 and air connec- ANSI/UL 723, Standard Test Method for Surface Burning tors complying with 4.3.2 shall be permitted. Characteristics of Building Materials, or 4.3.11.2.6.10 Materials that, in the form in which they are (3) Comply with 4.3.11.2.6.11 through 4.3.11.2.6.10, as used, shall have a potential heat value not exceeding applicable. 8141 kJ/kg (3500 Btu/lb), when tested in accordance with 4.3.11.2.6.1* Electrical wires and cables and optical fiber NFPA 259, Standard Test Method for Potential Heat of Building cables shall be listed as having a maximum peak optical den- Materials, and include either of the following: sity of 0.50 or less, an average optical density of 0.15 or less, (1) Materials having a structural base of noncombustible ma- and a maximum flame spread distance of 1.5 m (5 ft) or less terial, with a surfacing not exceeding a thickness of when tested in accordance with NFPA 262, Standard Method of 3.2 mm (1⁄8 in.) that has a flame spread index not greater Test for Flame Travel and Smoke of Wires and Cables for Use in Air- than 50 Handling Spaces, or shall be installed in metal raceways without (2) Materials, in the form and thickness used, having neither an overall nonmetallic covering, metal sheathed cable without a flame spread index greater than 25 nor evidence of con- an overall nonmetallic covering, or totally enclosed nonventi- tinued progressive combustion, and of such composition lated metallic busway without an overall nonmetallic covering. that surfaces that would be exposed by cutting through the material on any plane would have neither a flame 4.3.11.2.6.2 Pneumatic tubing for control systems shall be spread index greater than 25 nor evidence of continued listed as having a maximum peak optical density of 0.5 or less, progressive combustion, when tested in accordance with an average optical density of 0.15 or less, and a maximum ASTM E 84, Standard Test Method for Surface Burning Char- flame spread distance of 1.5 m (5 ft) or less when tested in acteristics of Building Materials, or ANSI/UL 723, Standard accordance with ANSI/UL 1820, Standard for Safety Fire Test of for Test for Surface Burning Characteristics of Building Pneumatic Tubing for Flame and Smoke Characteristics. Materials. 4.3.11.2.6.3 Nonmetallic fire sprinkler piping shall be listed 4.3.11.2.7 The accessible portion of abandoned materials ex- as having a maximum peak optical density of 0.5 or less, an posed to airflow shall be removed. average optical density of 0.15 or less, and a maximum flame spread distance of 1.5 m (5 ft) or less when tested in accor- 4.3.11.3 Apparatus Casing Plenum. dance with ANSI/UL 1887, Standard for Safety Fire Test of Plastic 4.3.11.3.1 A fabricated plenum and apparatus casing shall be Sprinkler Pipe for Visible Flame and Smoke Characteristics. permitted to be used for supply, return, or exhaust air service. 4.3.11.2.6.4 Signaling, optical fiber, and communications 4.3.11.3.2 Fabricated plenum and apparatus casing shall be raceways shall be listed as having a maximum peak optical constructed of materials and by methods specified in 4.3.1 and density of 0.50 or less, an average optical density of 0.15 or less, in accordance with the following: and a maximum flame spread distance of 1.5 m (5 ft) or less (1) The casing and plenum construction standards in when tested in accordance with ANSI/UL 2024, Standard for SMACNA HVAC Duct Construction Standards — Metal and Signaling, Optical Fiber and Communications Raceways and Cable Flexible Routing Assemblies. Cables installed within these raceways shall (2) ASHRAE Handbook — HVAC Systems and Equipment be listed as plenum cable in accordance with the requirements (3) Subsection 4.3.3 for all air duct coverings, duct lining, in 4.3.11.2.6.1. acoustical liner/cells, and miscellaneous materials 4.3.11.2.6.5* Loudspeakers, recessed lighting fixtures, and 4.3.11.3.3 Electrical wires and cables and optical fiber cables other electrical equipment with combustible enclosures, in- shall comply with 4.3.4. cluding their assemblies and accessories, nonmetallic cable ties, wraps, nonmetallic cable supports, and other discrete 4.3.11.4 Air-Handling Unit Room Plenum. products, shall be permitted in the ceiling cavity plenum 4.3.11.4.1 Individual rooms containing an air-handling where listed as having a maximum peak optical density of 0.5 unit(s) shall gather air from various sources and combine the or less, an average optical density of 0.15 or less, and a peak air within the room before returning it to the air-handling heat release rate of 100 kW or less when tested in accordance unit.

2015 Edition 90A–12 INSTALLATION OF AIR-CONDITIONING AND VENTILATING SYSTEMS

4.3.11.4.2 Duct covering, duct lining, acoustical liner/cells, 4.3.11.5.5.2 Pneumatic tubing for control systems shall be and miscellaneous materials shall comply with 4.3.3. listed as having a maximum peak optical density of 0.5 or less, an average optical density of 0.15 or less, and a maximum 4.3.11.4.3 Air-handling unit room plenums shall not be used flame spread distance of 1.5 m (5 ft) or less when tested in for storage or occupancy other than during equipment servic- accordance with ANSI/UL 1820, Standard for Safety Fire Test of ing. Pneumatic Tubing for Flame and Smoke Characteristics. 4.3.11.4.4 Accessible abandoned material shall be deemed to 4.3.11.5.5.3 Nonmetallic fire sprinkler piping shall be listed be in storage and shall be removed. Where cables are identi- as having a maximum peak optical density of 0.5 or less, an fied for future use with a tag, the tag shall be of sufficient average optical density of 0.15 or less, and a maximum flame durability to withstand the environment involved. spread distance of 1.5 m (5 ft) or less when tested in accor- 4.3.11.4.5 Materials used in the construction of an air- dance with ANSI/UL 1887, Standard for Safety Fire Test of Plastic handling unit room plenum shall be noncombustible or shall Sprinkler Pipe for Visible Flame and Smoke Characteristics. be limited combustible having a maximum smoke developed 4.3.11.5.5.4 Signaling, optical fiber, and communications index of 50 and shall be suitable for continuous exposure to raceways shall be listed as having a maximum peak optical the temperature and humidity conditions of the environmen- density of 0.50 or less, an average optical density of 0.15 or less, tal air in the plenum. and a maximum flame spread distance of 1.5 m (5 ft) or less 4.3.11.4.6* Electrical wires and cables and optical fiber cables when tested in accordance with ANSI/UL 2024, Standard for shall be listed as having a maximum peak optical density of Signaling, Optical Fiber and Communications Raceways and Cable 0.50 or less, an average optical density of 0.15 or less, and a Routing Assemblies. Cables installed within these raceways shall maximum flame spread distance of 1.5 m (5 ft) or less when be listed as plenum cable in accordance with the requirements tested in accordance with NFPA 262, Standard Method of Test for in 4.3.11.5.5.1. Flame Travel and Smoke of Wires and Cables for Use in Air-Handling 4.3.11.5.5.5 Raised floors, intermachine cables, electrical Spaces, or shall be installed in metal raceways, metal sheathed wires, listed plenum optical fiber, communications and signal- cable, or totally enclosed nonventilated busway. ing raceways, and optical-fiber cables in computer/data pro- 4.3.11.5 Raised Floor Plenum. cessing rooms where these rooms are designed and installed in accordance with NFPA 75, Standard for the Protection of Infor- 4.3.11.5.1 The space between the top of the finished floor mation Technology Equipment, shall be permitted. and the underside of a raised floor shall be permitted to be used to supply air to the occupied area or return or exhaust air 4.3.11.5.5.6 Loudspeakers, recessed lighting fixtures, and from or return and exhaust air from the occupied area, pro- other electrical equipment with combustible enclosures, in- vided that the conditions in 4.3.11.5.2 through 4.3.11.5.6 are cluding their assemblies and accessories, nonmetallic cable met. ties, wraps, nonmetallic cable supports, and other discrete products, shall be permitted in the raised floor plenum where 4.3.11.5.2 The integrity of the firestopping for penetrations listed as having a maximum peak optical density of 0.5 or less, shall be maintained. an average optical density of 0.15 or less, and a peak heat 4.3.11.5.3 The temperature of air delivered to these plenums release rate of 100 kW or less when tested in accordance with shall not exceed 121°C (250°F). ANSI/UL 2043, Standard for Safety Fire Test for Heat and Visible Smoke Release for Discrete Products and Their Accessories Installed in 4.3.11.5.4 Materials used in the construction of a raised floor Air-Handling Spaces. plenum shall be noncombustible or limited combustible materials, shall have a maximum peak smoke developed index of 4.3.11.5.5.7 Plastic piping and tubing used in plumbing sys- 50, and shall be suitable for continuous exposure to the tem- tems shall be permitted to be used within a raised floor ple- perature and humidity conditions of the environmental air in num if it exhibits a flame spread index of 25 or less and a the plenum. smoke developed index of 50 or less when tested in accordance with ASTM E 84, Standard Test Method for Surface Burning 4.3.11.5.5 Materials within a raised floor plenum exposed to Characteristics of Building Materials, or ANSI/UL 723, Standard the airflow shall: for Test for Surface Burning Characteristics of Building Materials, at (1) Be noncombustible, or full width of the tunnel and with no water or any other liquid (2) Exhibit a maximum flame spread index of 25 and a maxi- in the pipe during the test. mum smoke developed index of 50 when tested in accor- 4.3.11.5.5.8 Air ducts complying with 4.3.1.2 and air connec- dance with ASTM E 84, Standard Test Method for Surface tors complying with 4.3.2 shall be permitted. Burning Characteristics of Building Materials, or with ANSI/UL 723, Standard Test Method for Surface Burning 4.3.11.5.5.9 Materials, in the form in which they are used, Characteristics of Building Materials, or shall have a potential heat value not exceeding 8141 kJ/kg (3) Comply with 4.3.11.5.5.1 through 4.3.11.5.5.11, as (3500 Btu/lb) when tested in accordance with NFPA259, Stan- applicable. dard Test Method for Potential Heat of Building Materials, and include either of the following: 4.3.11.5.5.1* Electrical wires and cables and optical fiber cables shall be listed as having a maximum peak optical den- (1) Materials having a structural base of noncombustible ma- sity of 0.50 or less, an average optical density of 0.15 or less, terial, with a surfacing not exceeding a thickness of and a maximum flame spread distance of 1.5 m (5 ft) or less 3.2 mm (1⁄8 in.) that has a flame spread index not greater when tested in accordance with NFPA 262, Standard Method of than 50 Test for Flame Travel and Smoke of Wires and Cables for Use in Air- (2) Materials, in the form and thickness used, having neither Handling Spaces, or shall be installed in metal raceways, metal a flame spread index greater than 25 nor evidence of con- sheathed cable, or totally enclosed nonventilated busway. tinued progressive combustion, and of such composition

2015 Edition HVAC SYSTEMS 90A–13

that surfaces that would be exposed by cutting through consisting of 12.7 mm (0.5 in.) gypsum wallboard or a material the material on any plane would have neither a flame that is tested in accordance with and meets the acceptance spread index greater than 25 nor evidence of continued criteria of both the temperature transmission fire test and the progressive combustion, when tested in accordance with integrity fire test of NFPA 275, Standard Method of Fire Tests for ASTM E 84, Standard Test Method for Surface Burning Char- the Evaluation of Thermal Barriers Used Over Foam Plastic Insula- acteristics of Building Materials, or ANSI/UL 723, Standard tion, and shall exhibit a flame spread index of 75 or less and a for Test for Surface Burning Characteristics of Building smoke developed index of 450 or less when tested in accor- Materials. dance with ASTM E 84, Standard Test Method for Surface Burning Characteristics of Building Materials, or ANSI/UL 723, Standard 4.3.11.5.5.10 Smoke detectors shall not be required to meet for Test for Surface Burning Characteristics of Building Materials, at the requirements of 4.3.11.5.1. the maximum thickness intended for use. 4.3.11.5.5.11 Supplementary materials for air distribution sys- 4.3.12 Corridor Air Systems. tems shall be permitted provided they comply with 4.3.3. 4.3.11.5.6 The accessible portion of abandoned materials ex- 4.3.12.1 Egress Corridors. posed to airflow shall be removed. Where cables are identified L 4.3.12.1.1* Egress corridors in health care, detention and cor- for future use with a tag, the tag shall be of sufficient durability rectional, and residential occupancies shall not be used as a to withstand the environment involved. portion of a supply, return, or exhaust air system serving ad- 4.3.11.6 Wall or Ceiling Finish in Plenums. joining areas unless otherwise permitted by 4.3.12.1.3.1 through 4.3.12.1.3.4. 4.3.11.6.1 Wall or ceiling finish in plenums, except as indicated in 4.3.11.6.2, shall be noncombustible or shall exhibit a 4.3.12.1.2 Air movement between rooms and egress corri- flame spread index of 25 or less and a smoke developed index dors in hospitals, nursing facilities, and ambulatory care facili- of 50 or less, when tested in accordance with ASTM E 84, Stan- ties shall be permitted where the transfer of air is required for dard Test Method for Surface Burning Characteristics of Building clinical purposes by other standards. Materials, or ANSI/UL 723, Standard for Test for Surface Burning 4.3.12.1.3 An air transfer opening(s) shall not be permitted Characteristics of Building Materials, at the maximum thickness in walls or in doors separating egress corridors from adjoining intended for use. areas. 4.3.11.6.2 Foam plastic insulation shall not be used as wall or L 4.3.12.1.3.1 An air transfer opening(s) shall be permitted in ceiling finish in plenums unless the insulation meets one of walls or doors from toilet rooms, bathrooms, shower rooms, the criteria shown in 4.3.11.6.2.1, 4.3.11.6.2.2, or 4.3.11.6.2.3. sink closets, and similar auxiliary spaces opening directly onto 4.3.11.6.2.1 The foam plastic insulation material shall exhibit the egress corridor. a flame spread index of 25 or less and a smoke developed L 4.3.12.1.3.2 Where door clearances do not exceed those index of 50 or less when tested in accordance with ASTM E 84, specified for fire doors in NFPA 80, Standard for Fire Doors and Standard Test Method for Surface Burning Characteristics of Build- Other Opening Protectives, air transfer caused by pressure differ- ing Materials, or ANSI/UL 723, Standard for Test for Surface Burn- entials shall be permitted. ing Characteristics of Building Materials, at the maximum thickness intended for use, and shall comply with the following L 4.3.12.1.3.3 Use of egress corridors shall be permitted as part criteria: of an engineered smoke-control system. (1) Flame does not spread to the ceiling during the 40 kW L 4.3.12.1.3.4 Air transfer opening(s) shall be permitted in exposure. walls or in doors separating egress corridors from adjoining (2) Flame does not spread to the outer extremities of the areas in detention and correctional occupancies with corridor sample. separations of open construction (e.g., grating doors or grat- (3) Flashover does not occur. ing partitions). (4) The peak heat release rate does not exceed 800 kW. 4.3.12.2 Exits. Exit passageways, stairs, ramps, and other exits (5) The total smoke release does not exceed 1000 m2 2 shall not be used as a part of a supply, return, or exhaust air (1196 yd ) when tested in accordance with NFPA 286, system serving other areas of the building. Standard Methods of Fire Tests for Evaluating Contribution of Wall and Ceiling Interior Finish to Room Fire Growth (where 4.3.13* Smoke Control. Where a smoke-control or exhaust the testing shall be performed on the finished foam plas- system is required, it shall conform to the requirements of the tic assembly related to the actual end-use configuration building code of the authority having jurisdiction. and on the maximum thickness intended for use). 4.4 Materials. 4.3.11.6.2.2 The foam plastic insulation material shall be cov- 4.4.1* Noncombustible Material. ered by corrosion-resistant steel having a base metal thickness of not less than 0.4 mm (0.0160 in.) and shall exhibit a flame 4.4.1.1 A material that complies with any of the following spread index of 75 or less and a smoke developed index of 450 shall be considered a noncombustible material: or less when tested in accordance with ASTM E 84, Standard (1) A material that, in the form in which it is used and under Test Method for Surface Burning Characteristics of Building Materi- the conditions anticipated, will not ignite, burn, support als, or ANSI/UL 723, Standard for Test for Surface Burning Char- combustion, or release flammable vapors when subjected acteristics of Building Materials, at the maximum thickness in- to fire or heat tended for use. (2) A material that is reported as passing ASTM E 136, Stan- 4.3.11.6.2.3 The foam plastic insulation material shall be dard Test Method for Behavior of Materials in a Vertical Tube separated from the plenum by an approved thermal barrier Furnace at 750 Degrees C

2015 Edition 90A–14 INSTALLATION OF AIR-CONDITIONING AND VENTILATING SYSTEMS

(3) A material that is reported as complying with the pass/fail 5.1.3 Air-Handling Equipment Rooms That Have Air Ducts criteria of ASTM E 136 when tested in accordance with That Open Directly into a Shaft. the test method and procedure in ASTM E 2652, Standard 5.1.3.1 Air-handling equipment rooms, including the protec- Test Method for Behavior of Materials in a Tube Furnace with a tion of openings, shall be separated from shafts by construc- Cone-shaped Airflow Stabilizer, at 750 Degrees C tion having a fire resistance rating not less than that required [101:4.6.13.1] for the shaft by 5.3.4. 4.4.1.2 Where the term limited-combustible is used in this stan- 5.1.3.2 Fire-resistant separation shall not be required for air- dard, it shall also include the term noncombustible. [101:4.6.13.2] handling equipment rooms that are enclosed by construction having a fire resistance rating not less than that required for 4.4.2* Limited-Combustible Material. A material shall be con- the shaft. sidered a limited-combustible material where all the conditions of 4.4.2.1 and 4.4.2.2, and the conditions of either 4.4.2.3 5.1.4 Other Spaces Housing Air-Handling Units. Other spaces or 4.4.2.4, are met. [101:4.6.14] housing air-handling units shall meet the requirements of the building code of the authority having jurisdiction. 4.4.2.1 The material shall not comply with the requirements 5.2 Building Construction. for noncombustible material in accordance with 4.4.1. [101:4.6.14.1] 5.2.1 Air Duct Clearance. 4.4.2.2 The material, in the form in which it is used, shall 5.2.1.1 The clearance from metal air ducts used for heating exhibit a potential heat value not exceeding 3500 Btu/lb to assemblies constructed of combustible materials, including (8141 kJ/kg) where tested in accordance with NFPA 259, Stan- plaster on wood lath, shall be not less than 12.7 mm (1⁄2 in.), or dard Test Method for Potential Heat of Building Materials. the combustible material shall be protected with minimum [101:4.6.14.2] 6.35 mm (1⁄4 in.) thick approved insulating material. 4.4.2.3 The material shall have the structural base of a non- 5.2.1.2 The integrity of the firestopping and smokestopping combustible material with a surfacing not exceeding a thick- shall be maintained. ness of 1⁄8 in. (3.2 mm) where the surfacing exhibits a flame 5.2.1.3 The clearances provided in 5.2.1.1 shall not apply to spread index not greater than 50 when tested in accordance systems used solely for ventilation, air cooling, or air condi- with ASTM E 84, Standard Test Method for Surface Burning Char- tioning without heating. acteristics of Building Materials, or ANSI/UL 723, Standard for Test for Surface Burning Characteristics of Building Materials. 5.2.2 Structural Members. The installation of air ducts, in- [101:4.6.14.3] cluding the hangers, shall not reduce the fire resistance rating of structural members. 4.4.2.4 The material shall be composed of materials that, in 5.2.3 Ceiling Assemblies. Where the installation of the hang- the form and thickness used, neither exhibit a flame spread ers for the components of an air duct system penetrates an index greater than 25 nor evidence of continued progressive existing ceiling of a fire-resistive floor-ceiling or roof-ceiling combustion when tested in accordance with ASTM E 84, Stan- assembly and necessitates removal of a portion of that ceiling, dard Test Method for Surface Burning Characteristics of Building the replacement material shall be identical to that which was Materials, or ANSI/UL 723, Standard for Test for Surface Burning removed or shall be approved as equivalent to that which was Characteristics of Building Materials, and shall be of such compo- removed. sition that all surfaces that would be exposed by cutting through the material on any plane would neither exhibit a 5.2.4 As an alternative to repairing the existing ceiling, a new flame spread index greater than 25 nor exhibit evidence of ceiling shall be permitted to be installed below the air duct continued progressive combustion when tested in accordance system, provided the fire resistance rating of the floor-ceiling with ASTM E 84 or ANSI/UL 723. [101:4.6.14.4] or roof-ceiling design is not reduced. 4.4.2.5 Where the term limited-combustible is used in this stan- 5.3* Penetrations — Protection of Openings. dard, it shall also include the term noncombustible.[101:4.6.14.5] 5.3.1 Fire-Rated Walls and Partitions. 5.3.1.1* Approved fire dampers shall be provided where air ducts penetrate or terminate at openings in walls or partitions L Chapter 5 Integration of a Ventilation and required to have a fire resistance rating of 2 hours or more. Air-Conditioning System(s) with Building Construction 5.3.1.1.1* Fire dampers shall not be required where other openings through the wall are not required to be protected. 5.1 Air-Handling Equipment Rooms. 5.3.1.2 Approved fire dampers shall be provided in all air 5.1.1 General. Air-handling equipment rooms shall be classi- transfer openings in partitions that are required to have a fire fied into the following three categories: resistance rating and in which other openings are required to (1) Those used as air plenums (usually return air) be protected. (2) Those with air ducts that open directly into a shaft 5.3.2 Floors Required to Have a Fire Resistance Rating. (3) Other air-handling unit rooms 5.3.2.1 Where air ducts extend through only one floor and 5.1.2 Air-Handling Equipment Rooms Used as Plenum Space. serve only two adjacent stories, the air ducts shall be enclosed Air-handling equipment rooms used as plenums for supply or (see 5.3.4.1), or fire dampers shall be installed at each point return air shall comply with 4.3.11.4. where the floor is penetrated.

2015 Edition INTEGRATION OF A VENTILATION AND AIR-CONDITIONING SYSTEM(S) WITH BUILDING CONSTRUCTION 90A–15

5.3.3* Floor-Ceiling or Roof-Ceiling Assemblies Having a Fire L 5.3.4.6.2 A fire damper shall not be required where the fol- Resistance Rating. lowing conditions exist: 5.3.3.1 Where air ducts and openings for air ducts are used in (1) Branch ducts connect to enclosed exhaust risers meeting a floor-ceiling or roof-ceiling assembly that is required to have the requirements of 5.3.4.1 or 5.3.4.4. a fire resistance rating, all the materials and the construction (2) The airflow moves upward. of the assembly, including the air duct materials and the size (3) Steel subducts at least 560 mm (22 in.) in length are car- and protection of the openings, shall conform with the design ried up inside the riser from each inlet. of the fire-resistive assembly, as tested in accordance with (4) The riser is appropriately sized to accommodate the flow ASTM E 119, Standard Test Methods for Fire Tests of Building Con- restriction created by the subduct. struction and Materials, or ANSI/UL 263, Standard for Fire Tests of Building Construction and Materials. 5.3.5 Smoke Barriers. 5.3.3.2 Where dampers are required, they shall be located in 5.3.5.1 Smoke dampers shall be installed at or adjacent to the accordance with 5.4.4. point where air ducts pass through required smoke barriers, but in no case shall a smoke damper be installed more than 5.3.4 Shafts. 0.6 m (2 ft) from the barrier or after the first air duct inlet or outlet, whichever is closer to the smoke barrier, unless other- 5.3.4.1 Air ducts that pass through the floors of buildings that wise permitted by 5.3.5.1.1 through 5.3.5.1.5. require the protection of vertical openings shall be enclosed with partitions or walls constructed of materials as permitted 5.3.5.1.1 Smoke dampers shall not be required on air systems by the building code of the authority having jurisdiction, as other than where necessary for the proper functioning of that indicated in 5.3.4.2 or 5.3.4.3, unless otherwise permitted by system where the system is designed specifically to accomplish 5.3.4.3.1. the following: L 5.3.4.2 The shaft enclosure shall have a minimum fire resis- (1) Function as an engineered smoke-control system, includ- tance rating (based on possible fire exposure from either side ing the provision of continuous air movement with the of the partition or wall) of 1 hour where such air ducts are air-handling system located in a building less than four stories in height. (2) Provide air to other areas of the building during a fire emergency 5.3.4.3 The shaft enclosure shall have a minimum fire resis- (3) Provide pressure differentials during a fire emergency tance rating (based on possible fire exposure from either side of the partition or wall) of 2 hours where such air ducts are 5.3.5.1.2 Smoke dampers shall not be required to be located located in a building four stories or more in height. within a prescribed distance of a smoke barrier where isolation smoke dampers complying with 4.3.9.2 are used in air- 5.3.4.3.1 Where an air duct penetrates only one floor or one handling equipment. floor and an air-handling equipment penthouse floor, and the air duct contains a fire damper located where the duct pen- 5.3.5.1.3 Smoke dampers shall not be required where the air etrates the floor, an air duct enclosure shall not be required. inlet or outlet openings in ducts are limited to a single smoke compartment. 5.3.4.4 A fire-resistive enclosure used as an air duct shall conform with 4.3.1 and with 5.3.4.2 through 5.3.4.3.1. 5.3.5.1.4 Smoke dampers shall not be required in ducts where the air continues to move and the air-handling system 5.3.4.4.1 Gypsum board systems shall be constructed in ac- installed is arranged to prevent recirculation of exhaust or cordance with GA 600, Fire Resistance Design Manual. return air under fire emergency conditions. L 5.3.4.5 Shafts that constitute air ducts or that enclose air 5.3.5.1.5* Smoke dampers shall not be required in occupan- ducts used for the movement of environmental air shall not cies where exempted by NFPA 101, Life Safety Code, or enclose the following: NFPA 5000, Building Construction and Safety Code. (1) Exhaust ducts used for the removal of smoke- and grease- 5.3.5.2 Where penetration of a smoke barrier is required to laden vapors from cooking equipment be provided with a fire damper, a combination fire and smoke (2) Ducts used for the removal of flammable vapors damper equipped and arranged to be both smoke responsive (3) Ducts used for moving, conveying, or transporting stock, and heat responsive shall be permitted. vapor, or dust (4) Ducts used for the removal of nonflammable corrosive 5.4 Fire Dampers, Smoke Dampers, and Ceiling Dampers. fumes and vapors 5.4.1 Fire Dampers. (5) Refuse and linen chutes (6) Piping, except for noncombustible piping conveying wa- 5.4.1.1 Fire dampers used for the protection of openings in ter or other nonhazardous or nontoxic materials walls, partitions, or floors with fire resistance ratings of less (7) Combustible storage than 3 hours shall have a 11⁄2-hour fire protection rating in accordance with ANSI/UL 555, Standard for Safety Fire Dampers. L 5.3.4.6 Fire dampers shall be installed at each direct or ducted opening into and out of enclosures required by 5.4.2 Fire dampers used for the protection of openings in 5.3.4.1, unless otherwise permitted by 5.3.4.6.1 or 5.3.4.6.2. walls, partitions, or floors having a fire resistance rating of 3 hours or more shall have a 3-hour fire protection rating in L 5.3.4.6.1 A fire damper shall not be required where an air accordance with ANSI/UL 555, Standard for Safety Fire Dampers. duct system serving only one story is used only for exhaust of air to the outside and is contained within its own dedicated 5.4.3* Smoke Dampers. Smoke dampers used for the protec- shaft. tion of openings in smoke barriers or in engineered smoke-

2015 Edition 90A–16 INSTALLATION OF AIR-CONDITIONING AND VENTILATING SYSTEMS control systems shall be classified in accordance with 5.4.5.4.3 Fire dampers, smoke dampers, and combination ANSI/UL 555S, Standard for Safety Smoke Dampers. fire/smoke dampers shall not be required in ducts used for kitchen or clothes dryer exhaust systems. 5.4.3.1 Smoke damper leakage ratings shall meet, as a minimum, Class II, and elevated temperature ratings shall be not 5.4.6 Damper Location Information. less than 121°C (250°F). 5.4.6.1 The locations and mounting arrangement of all fire 5.4.4 Ceiling Dampers. dampers, smoke dampers, ceiling dampers, and fire protection means of a similar nature required by this standard shall 5.4.4.1* Ceiling dampers or other methods of protecting be shown on the drawings of the air duct systems. openings in rated floor-ceiling or roof-ceiling assemblies shall comply with the construction details of the tested floor-ceiling 5.4.6.2 Dampers required to close in airflow shall have the or roof-ceiling assembly or with listed ceiling air diffusers or calculated airflow at their location shown on the drawings of listed ceiling dampers. the air duct system. 5.4.4.2 Ceiling dampers shall be tested in accordance with 5.4.7 Installation. ANSI/UL 555C, Standard for Safety Ceiling Dampers. 5.4.7.1* Fire dampers, including their sleeves; smoke damp- 5.4.5 Damper Closure. ers; and ceiling dampers shall be installed in accordance with the conditions of their listings and the manufacturer’s instal- 5.4.5.1 All fire dampers and ceiling dampers shall close auto- lation instructions and the requirements of NFPA 80, Standard matically. for Fire Doors and Other Opening Protectives. 5.4.5.1.1 All fire dampers and ceiling dampers shall remain 5.4.7.2 Smoke dampers shall be installed in accordance with closed upon the operation of a listed fusible link or other the conditions of their listings, the manufacturer’s installation approved heat-actuated device located where it will be readily instructions, and the requirements of NFPA 105, Standard for affected by an abnormal rise of temperature. Smoke Door Assemblies and Other Opening Protectives. 5.4.5.2 Fusible Links. 5.4.8 Maintenance. 5.4.5.2.1 Fusible links shall have a temperature rating ap- L 5.4.8.1 Fire dampers and ceiling dampers shall be main- proximately 28°C (50°F) above the maximum temperature tained in accordance with NFPA 80, Standard for Fire Doors and that normally is encountered when the system is in operation Other Opening Protectives. or shut down. 5.4.8.2 Smoke dampers shall be maintained in accordance 5.4.5.2.2 Fusible links shall have a temperature rating not less with NFPA 105, Standard for Smoke Door Assemblies and Other than 71°C (160°F). Opening Protectives. 5.4.5.2.2.1* Where combination fire and smoke dampers are located within air ducts that are part of an engineered smoke- control system, fusible links or other approved heat- L Chapter 6 Controls responsive devices shall have a temperature rating approximately 28°C (50°F) above the maximum smoke-control system 6.1 Wiring. The installation of electrical wiring and equip- designed operating temperature. ment associated with the operation and control of air- 5.4.5.2.2.2 The combination fire and smoke dampers shall conditioning and ventilating systems shall be in accordance not exceed the ANSI/UL 555S, Standard for Safety Smoke Damp- with NFPA 70, National Electrical Code. ers, degradation test temperature rating of the combination 6.2 Manual Control. fire and smoke damper. 6.2.1 Each air distribution system shall be provided with at 5.4.5.2.2.3 The combination fire and smoke dampers shall least one manually operable means for stopping the operation not exceed a maximum temperature rating of 177°C (350°F). of the supply, return, and exhaust fan(s) in an emergency. 5.4.5.3 A provision for remote opening of combination fire 6.2.2 The means of manual operation shall be located at an and smoke dampers, where necessary for smoke removal, shall approved location. be permitted. 6.3* Smoke Dampers. 5.4.5.3.1 Combination fire and smoke dampers permitted in 5.4.5.3 shall have provisions that allow them to reclose auto- L 6.3.1 Smoke dampers shall be controlled by an automatic matically upon reaching the damper’s maximum degradation alarm-initiated device. test temperature in accordance with ANSI/UL 555S, Standard for Safety Smoke Dampers. 6.3.2* Smoke dampers shall be permitted to be positioned manually from a command station. 5.4.5.4* Dampers shall close against the maximum calculated airflow of that portion of the air duct system in which they are 6.3.3 Smoke dampers installed to isolate the air-handling sys- installed. tem in accordance with 4.3.10.2 shall be arranged to close automatically when the system is not in operation. 5.4.5.4.1 Fire dampers shall be tested for closure in accordance with ANSI/UL 555, Standard for Safety Fire Dampers. 6.3.4* Smoke dampers shall be permitted to remain open when their associated fan is off, provided their associated con- 5.4.5.4.2 Smoke dampers shall be tested for closure in accor- trolling damper actuators and automatic alarm-initiating de- dance with ANSI/UL 555S, Standard for Safety Smoke Dampers. vices remain operational.

2015 Edition ANNEX A 90A–17

6.4* Smoke Detection for Automatic Control. L Chapter 7 Acceptance Testing L 6.4.1 Testing. All automatic shutdown devices shall be tested 7.1 General. at least annually. 7.1.1* An acceptance test shall be performed to determine 6.4.2* Location. that the protective measures required in this standard function when needed in order to restrict the spread of fire and 6.4.2.1 Smoke detectors listed for use in air distribution sys- smoke. tems shall be located as follows: 7.1.2 Records shall be maintained on acceptance test results. L (1) Downstream of the air filters and ahead of any branch connections in air supply systems having a capacity 7.1.2.1 Records shall be available for inspection. 3 greater than 944 L/sec (2000 ft /min) 7.2* Fire Dampers, Smoke Dampers, and Ceiling Dampers. All (2) At each story prior to the connection to a common return fire dampers, smoke dampers, and ceiling dampers shall be and prior to any recirculation or fresh air inlet connec- operated prior to the occupancy of a building to determine tion in air return systems having a capacity greater than 3 that they function in accordance with the requirements of this 7080 L/sec (15,000 ft /min) and serving more than one standard. story 7.3 Controls and Operating Systems. L 6.4.2.2 Return system smoke detectors shall not be required where the entire space served by the air distribution system is 7.3.1* Controls required by Chapter 6 shall be tested for com- protected by a system of area smoke detectors. pliance with the requirements of this standard. 7.3.2 Acceptance tests of fire protection devices in air- L 6.4.2.3 Smoke detectors shall not be required for fan units conditioning and ventilating systems shall, as far as practi- whose sole function is to remove air from the inside of the cable, be performed under normal operating conditions. building to the outside of the building. 7.3.3 Portions of control or alarm systems are permitted to 6.4.3* Function. have standby power or other emergency modes of operation. 6.4.3.1 Smoke detectors provided as required by 6.4.2 shall 7.3.4 The tests shall be performed to determine that the sys- automatically stop their respective fan(s) on detecting the tem operates under the standby power or emergency opera- presence of smoke. tion mode conditions as well as under normal conditions. 6.4.3.2 Where the return air fan is functioning as part of an engineered smoke-control system and a different mode is required, the smoke detectors shall not be required to automati- L Annex A Explanatory Material cally stop their respective fans. Annex A is not a part of the requirements of this NFPA document 6.4.4 Installation. but is included for informational purposes only. This annex contains 6.4.4.1 Smoke detectors shall be installed, tested, and main- explanatory material, numbered to correspond with the applicable text tained in accordance with NFPA 72, National Fire Alarm and paragraphs. Signaling Code. A.1.1 An air duct system has the potential to convey smoke, hot gases, and flame from area to area and to supply air to aid 6.4.4.2 In addition to the requirements of 6.4.3, where an combustion in the fire area. For these reasons, fire protection approved fire alarm system is installed in a building, the of an air duct system is essential to safety to life and the protec- smoke detectors required by the provisions of Section 6.4 shall tion of property. However, an air duct system’s fire integrity be connected to the fire alarm system in accordance with the also enables it to be used as part of a building’s fire protection requirements of , NFPA 72 National Fire Alarm and Signaling system. Code. Guidance for the design of smoke-control systems is pro- 6.4.4.2.1 Smoke detectors used solely for closing dampers or vided in NFPA 92, Standard for Smoke Control Systems. for heating, ventilating, and air-conditioning system shutdown Pertinent information on maintenance is provided in shall not be required to activate the building evacuation Annex B. alarm. Maintenance of fire dampers, ceiling dampers, smoke dampers, and combination fire/smoke dampers require- 6.4.4.3 Where smoke detectors required by Section 6.4 are ments can be found in NFPA 80, Standard for Fire Doors and installed in a building not equipped with an approved fire Other Opening Protectives, and NFPA 105, Standard for Smoke Door alarm system as specified by 6.4.4.2, the following shall occur: Assemblies and Other Opening Protectives. (1) Smoke detector activation required by Section 6.4 shall A.1.3(1) For the purposes of this standard, a space is consid- cause a visual signal and an audible signal in a normally ered as an entire building or a portion thereof separated from occupied area. all other portions of the building by fire resistance–rated con- (2) Smoke detector trouble conditions shall be indicated vi- struction and whose environmental air does not mix with that sually or audibly in a normally occupied area and shall be of any other space. [For spaces not exceeding 708 m3 identified as air duct detector trouble. (25,000 ft3) in volume, see NFPA 90B, Standard for the Installa- tion of Warm Air Heating and Air-Conditioning Systems.] 6.4.4.4 Smoke detectors powered separately from the fire alarm system for the sole function of stopping fans shall not A.1.3(2) For construction types, see NFPA 220, Standard on require standby power. Types of Building Construction.

2015 Edition 90A–18 INSTALLATION OF AIR-CONDITIONING AND VENTILATING SYSTEMS

A.1.3(3) Such applicable standards include, but are not lim- A.3.3.10 Air Outlet. For further discussion of various types of ited to, NFPA 70, National Electrical Code (see Ventilation in in- air outlet devices, see ASHRAE Handbook — Fundamentals, dex), and NFPA 90B, Standard for the Installation of Warm Air Chapter 32, “Space Air Diffusion.” Heating and Air-Conditioning Systems. A.3.3.14.1 Ceiling Damper. Some such devices are listed in A.1.3(4) Such applicable standards include, but are not lim- UL Fire Resistance Directory under the category “Ceiling Damper ited to, NFPA 31, Standard for the Installation of Oil-Burning (CABS).” Equipment; NFPA 33, Standard for Spray Application Using Flam- mable or Combustible Materials; NFPA 34, Standard for Dipping, A.3.3.14.3 Fire Damper. Some such devices are listed in Coating, and Printing Processes Using Flammable or Combustible Liq- UL Heating, Cooling, Ventilating and Cooking Equipment Directory under the category of “Fire Dampers for Fire Barrier and uids; NFPA 45, Standard on Fire Protection for Laboratories Using Smoke Applications (EMME).” Fire dampers are classified for Chemicals; NFPA 70, National Electrical Code (see Ventilation in use in either static systems or for dynamic systems, where the index); NFPA 75, Standard for the Protection of Information Tech- dampers are rated for closure under airflow. nology Equipment; NFPA 91, Standard for Exhaust Systems for Air Conveying of Vapors, Gases, Mists, and Noncombustible Particulate A.3.3.14.4 Smoke Damper. Smoke dampers are subjected to Solids; and NFPA 96, Standard for Ventilation Control and Fire Pro- various pressure differentials, are exposed to elevated tem- tection of Commercial Cooking Operations. peratures, and can be required to open or close against me- chanically induced airflow. Some such devices are listed in A.3.2.1 Approved. The National Fire Protection Association UL Heating, Cooling, Ventilating and Cooking Equipment Directory does not approve, inspect, or certify any installations, proce- under the category “Dampers for Fire Barrier and Smoke Ap- dures, equipment, or materials; nor does it approve or evalu- plications (EMME).” ate testing laboratories. In determining the acceptability of installations, procedures, equipment, or materials, the author- A.3.3.17 Fire Resistance Rating. Some such assemblies are ity having jurisdiction may base acceptance on compliance listed in UL Fire Resistance Directory under the categories with NFPA or other appropriate standards. In the absence of “Floors,” “Roofs,” and “Walls and Partitions.” such standards, said authority may require evidence of proper A.3.3.19 Flame Spread Index. Flame spread indexes for some installation, procedure, or use. The authority having jurisdic- materials are listed in UL Building Materials Directory. Classifica- tion may also refer to the listings or labeling practices of an tions have been developed using flame spread index values. organization that is concerned with product evaluations and is thus in a position to determine compliance with appropriate A.3.3.21 Limited-Combustible (Material). Material subject to standards for the current production of listed items. increase in combustibility or flame spread index beyond the limits herein established through the effects of age, mois- A.3.2.2 Authority Having Jurisdiction (AHJ). The phrase “au- ture, or other atmospheric condition is considered combus- thority having jurisdiction,” or its acronym AHJ, is used in tible. See NFPA 259, Standard Test Method for Potential Heat of NFPA documents in a broad manner, since jurisdictions and Building Materials, and NFPA 220, Standard on Types of Build- approval agencies vary, as do their responsibilities. Where pub- ing Construction. lic safety is primary, the authority having jurisdiction may be a federal, state, local, or other regional department or indi- A.3.3.22 Noncombustible Material. A material that is re- vidual such as a fire chief; fire marshal; chief of a fire preven- ported as complying with the pass/fail criteria of ASTM E 136, tion bureau, labor department, or health department; build- Standard Test Method for Behavior of Materials in a Vertical Tube ing official; electrical inspector; or others having statutory Furnace at 750°C, when tested in accordance with the test authority. For insurance purposes, an insurance inspection de- method and procedure in ASTM E 2652, Standard Test Method partment, rating bureau, or other insurance company repre- for Behavior of Materials in a Tube Furnace with a Cone-Shaped sentative may be the authority having jurisdiction. In many Airflow Stabilizer, at 750°C, is considered a noncombustible ma- circumstances, the property owner or his or her designated terial. agent assumes the role of the authority having jurisdiction; at A.3.3.23 Plenum. A plenum can be one of the following five government installations, the commanding officer or depart- described types of unoccupied chambers through which air mental official may be the authority having jurisdiction. flows at low velocity and with little change in static pressure: A.3.2.3 Listed. The means for identifying listed equipment (1) Supply air plenum. Any plenum at any point on the dis- may vary for each organization concerned with product evalu- charge side of a fan through which air is intentionally ation; some organizations do not recognize equipment as conveyed to a space or spaces within a building. listed unless it is also labeled. The authority having jurisdic- (2) Return air plenum. Any plenum at any point on the intake tion should utilize the system employed by the listing organi- side of a fan through which air is intentionally conveyed zation to identify a listed product. from a space or spaces within the building to the fan for A.3.3.3 Air Connector. Some such devices are listed in UL eventual complete or partial return to the same space or Heating, Cooling, Ventilating and Cooking Equipment Directory un- spaces. der the category “Connectors (ALNR).” Because these devices (3) Exhaust air plenum. Any plenum at any point on the intake do not meet all the requirements for air ducts, they have limi- side of a fan through which air is intentionally removed tations on their use, length, and location. (For limitations on the from a space or spaces within the building for discharge use of air connectors, see 4.3.2.1.) to the exterior of the building. (4) Outside air plenum. Any plenum at any point on the intake A.3.3.9 Air Inlet. For further discussion of various types of air side of a fan through which air from the exterior of the inlet devices, see ASHRAE Handbook — Fundamentals, Chapter 32, building is intentionally introduced into the building or “Space Air Diffusion.” its ventilation system(s).

2015 Edition ANNEX A 90A–19

(5) Mixed-air plenum. Any plenum at any point on the intake Many fire dampers and smoke dampers are preloaded with side of a fan through which air is intentionally conveyed powerful springs that force the damper to shut. These damp- from a space or spaces within the building and from the ers need to be opened against these springs, which could ne- exterior of the building to the fan for eventual complete cessitate the ability to get two arms into the duct. or partial return to the same space or spaces. A.4.3.4.4 Electrical wires and cables and optical fiber cables A.3.3.25 Smoke Barrier. A smoke barrier might be vertically installed in metal raceways or metal sheathed cable are not or horizontally aligned, such as a wall, floor, or ceiling assem- considered to be exposed to the airflow and need not meet bly. A smoke barrier might or might not have a fire resistance the requirements of 4.3.4.4. Electrical wires and cables and rating. See NFPA 101, Life Safety Code, Chapter 8, for additional optical fiber cables listed to UL Subject 2424, Outline of Investi- guidance. gation for Cable Marked Limited Combustible, are considered to be suitable for use wherever cables tested in accordance with A.3.3.27 Smoke Detector. See NFPA 72, National Fire Alarm and NFPA 262, Standard Method of Test for Flame Travel and Smoke of Signaling Code. Wires and Cables for Use in Air-Handling Spaces, are required. A.3.3.28 Smoke Developed Index. Smoke developed indexes for some materials are listed in UL Building Materials Directory. A.4.3.11.2.6.1 Electrical wires and cables and optical fiber Classifications have been developed using smoke developed cables listed to UL Subject 2424, Outline of Investigation for Cable index values. Marked Limited Combustible, are considered to be suitable for use wherever cables tested in accordance with NFPA 262, Stan- A.4.2.1.2 The location of outside air intakes, including in- dard Method of Test for Flame Travel and Smoke of Wires and Cables takes located on roofs, needs to be carefully selected to avoid for Use in Air-Handling Spaces, are required. drawing in objectionable materials, including, but not limited to, combustible materials and toxic or hazardous vapors. The A.4.3.11.2.6.5 Nonmetallic cable ties listed to ANSI/UL 62275, location should consider proximity to emergency smoke ex- Cable Management Systems—Cable Ties for Electrical Installations, and haust, garage exhaust, discharge of kitchen hood vents, and nonmetallic cable supports listed to ANSI/UL 1565, Positioning other objectionable discharges from the building or adjacent Devices, and marked for use in plenums are considered suitable structures. for use wherever nonmetallic cable ties or nonmetallic cable sup- A.4.2.2.2 For care and maintenance, see Annex B. ports tested in accordance with ANSI/UL 2043, Standard for Safety Fire Test for Heat and Visible Smoke Release for Discrete Products and A.4.3 Abandoned wires, cables, and other building service Their Accessories Installed in Air-Handling Spaces, are required. materials exposed to airflow result in an unnecessary increase in fuel load. Where practical, installation locations and meth- A.4.3.11.4.6 Electrical wires and cables and optical fiber ods that anticipate and facilitate the removal of such materials cables installed in metal raceways without an overall nonme- should be selected. tallic covering, metal sheathed cable without an overall non- A.4.3.3.1 ASTM E 2231, Standard Practice for Specimen Prepara- metallic covering, or totally enclosed nonventilated busway tion and Mounting of Pipe and Duct Insulation Materials to Assess without an overall nonmetallic covering are not considered to Surface Burning Characteristics, is a practice that describes, in be exposed to the airflow and need not meet the requirements mandatory language, standard methods for specimen prepa- of 4.3.11.4.6. Electrical wires and cables and optical fiber ration and mounting of pipe and duct insulation systems using cables listed to UL Subject 2424, Outline of Investigation for Cable the Steiner tunnel test method (contained in ASTM E 84, Stan- Marked Limited Combustible, are considered to be suitable for dard Test Method for Surface Burning Characteristics of Building use wherever cables tested in accordance with NFPA 262, Stan- Materials). It requires that the entire system that is used in the dard Method of Test for Flame Travel and Smoke of Wires and Cables field be tested, including the insulation itself, any adhesive, for Use in Air-Handling Spaces, are required. and/or any jacket used. The practice recognizes that pipe or A.4.3.11.5.5.1 Electrical wires and cables and optical fiber duct insulation systems can comprise a single product or of a cables listed to UL Subject 2424, Outline of Investigation for Cable combination of products, and that these systems have a variety Marked Limited Combustible, are considered to be suitable for of physical characteristics, including that they may or may not use wherever cables tested in accordance with NFPA 262, Stan- be self-supporting. dard Method of Test for Flame Travel and Smoke of Wires and Cables A.4.3.3.5 See NAIMA Fibrous Glass Duct Liner Standard and for Use in Air-Handling Spaces, are required. NAIMA Fibrous Glass Duct Construction Standards for additional information. A.4.3.12.1.1 See ANSI/ASHRAE/ASHE Standard 170, Venti- lation of Health Care Facilities. A.4.3.3.7 It is the intent of the committee that wall and ceiling finish in ceiling plenums comply with 4.3.3.7 and not A.4.3.13 For further information, see NFPA 92, Standard for 4.3.3.1. Smoke Control Systems. A.4.3.4.1 Access doors for fire dampers should be located so A.4.4.1 The provisions of 4.4.1 do not require inherently that the spring catch and fusible links are accessible when the noncombustible materials to be tested in order to be classified damper is closed. Where the size of the duct permits, the mini- as noncombustible materials. mum access door size should be 457 mm × 406 mm A.4.4.2 Materials subject to increase in combustibility or (18 in. × 16 in.). For dampers that are too large for an ordinary flame spread index beyond the limits herein established person’s arms to reach from outside the duct to reset the damper through the effects of age, moisture, or other atmospheric and replace the fusible link, the minimum size for the access condition are considered combustible. (See NFPA 259, Stan- door should be increased to 610 mm × 406 mm (24 in. × 16 in.) to dard Test Method for Potential Heat of Building Materials, and allow the entrance of an individual. NFPA 220, Standard on Types of Building Construction.) Access doors should be located as close as practicable to fire dampers and smoke dampers. If feasible, the underside of A.5.3 For examples of the application of the penetration pro- the duct should be used rather than a side door. tection requirements, see Figure A.5.3.

2015 Edition 90A–20 INSTALLATION OF AIR-CONDITIONING AND VENTILATING SYSTEMS

Fire-rated roof-ceiling assembly

FD 24 Exhaust fan Protection at these penetrations needs to conform FD, see 5.3.4.6 to the rated roof-ceiling assembly, see 5.3.3 Rooftop AC 23 AC FD, see 5.3.2 term. unit, FD term. see 5.3.3 See 4.3.8.3 & 4.3.9 device device

FD 22 FD FD Nonrated 21 ceiling 20 19 See 4.3.8.3 & 4.3.9

FD 22 in. FD, See 5.3.4.6.2 see 5.3.4.6 FD, 2-hr partition Smoke barrier, FD FD see 5.3.1.1 1-hr see 5.3.5 SD, see Return 14 FD, see 5.3.2 partition 15 5.3.5.1 16 17 18 air, see See 4.3.8.3 4.3.1.3.1 & 4.3.9 Nonrated & 5.3.4.4 partition FD Rated partition less than 2 hours 7 See 5.3.4.1 FD 12 Air transfer 11 8 FD opening Air transfer opening, 9 See 4.3.8.3 & 4.3.9 FD see 5.3.1.2 10 13

See 5.3.5.1 & 5.3.5 FD FD Masonry/ SDs (not required if gypsum SD, see 4.3.10.2 SD FD exhaust shaft, 1-hr partition combination 2-hr Outside air FDs, see 5.3.1.1 see 5.3.4 1 2 FD/SD provided) partition & smoke barrier (or combination FD/SD, intake see 5.3.5.2) 6 FD, see 4.2.1.2 See 5.1.3 FD Air transfer opening, 3 4 5 see 5.3.1.2

Notes: Return/exhaust duct requirements are similar. SD = Smoke damper FD = Fire damper

1 2 3 . . . . = Space identification

FIGURE A.5.3 Application of Penetration Requirements.

A.5.3.1.1 Duct penetrations of fire walls should be avoided. combination dampers, was not available. Fire dampers in accordance with ANSI/UL 555, Standard for Safety Fire Dampers, A.5.3.1.1.1 Fire dampers are recommended in order to iso- are listed with maximum 141°C (286°F) links. It is recognized late specific hazards. that, in some unusual cases, an engineered smoke-control sys- A.5.3.3 For information on designs of fire-resistive assemblies tem can make higher temperature links desirable for proper incorporating air-handling components, see UL Fire Resistance operation. This arrangement necessitates a case-by-case con- Directory, “Floor-Ceiling Designs” or “Roof-Ceiling Designs.” sideration and concurrence by the authority having jurisdiction. A.5.3.5.1.5 Smoke dampers exempted by NFPA 101, Life Safety Code, for health care occupancies include dampers in A.5.4.5.4 On closure of certain smoke dampers in smoke- duct penetrations of smoke barriers in fully ducted heating, control systems, the total system flow decreases, but the duct ventilating, and air-conditioning systems. velocity at open fire dampers can be as high as roughly 600 percent of the initial duct design velocity. The dynamic A.5.4.3 The designer should specify the leakage class, maxi- airflow and pressure rating of the damper must be adequate mum pressure, maximum velocity, installation mode (hori- for the damper to close under airflow at the damper’s closure zontal or vertical), and degradation test temperature of the pressure. The damper face velocity and closure pressure can damper. be approximated by calculation. The calculated values must A.5.4.4.1 For information on other methods of protecting be specified because UL labels dynamic fire dampers at openings in rated floor-ceiling or roof-ceiling assemblies, see 5 m/sec (1000 ft/min) increments, starting at 10 m/sec the UL Fire Resistance Directory design information section for (2000 ft/min). duct outlet protection. System A can be used only when it is A.5.4.7.1 Fire dampers are of no fire protection value un- specified in the individual design. System B can be used in any less they remain in place in the protected opening in the design that contains a steel duct with the duct outlet protected event that the ductwork collapses during a fire. To accom- by a hinged door damper, for equal or smaller outlet size. The plish this, ductwork should not be continuous through a systems have been investigated for their effectiveness in retard- partition opening but instead should connect on each side ing the transfer of heat into the ceiling space, but their ability of the partition to a damper installed in a sleeve or frame to retard smoke and other combustion products has not been secured by perimeter-mounting angles on both sides of the investigated. opening or be installed per the listing of the device. For A.5.4.5.2.2.1 The exception to this paragraph in earlier edi- specific details regarding sleeve thickness, perimeter angle tions applied to fire dampers, due to the fact that dimensions, size and frequency of fasteners, clearance for ANSI/UL 555S, Standard for Safety Smoke Dampers, which tested expansion, duct-sleeve connections, and fire damper access

2015 Edition ANNEX B 90A–21 doors, the manufacturer’s installation instructions and gency. The access openings required in 4.3.4 should be SMACNA Fire, Smoke and Radiation Damper Installation Guide checked for proper location, function, and size during the for HVAC Systems should be referenced. acceptance testing. A.6.3 The dampers should close as quickly as practicable, Maintenance recommendations, including cleaning, re- subject to requirements of the system fan and air duct charac- pairing, and periodic testing, are provided in Annex B. teristics. The designer should evaluate whether the smoke A.7.2 See NFPA 105, Standard for Smoke Door Assemblies and dampers normally should be open or closed and should con- Other Opening Protectives, for testing requirements for smoke sider the fail-safe position of the dampers during an event dampers and combination fire and smoke dampers. See such as a power failure. NFPA80, Standard for Fire Doors and Other Opening Protectives, for testing requirements for fire dampers. AMCA International’s A.6.3.2 Within the scope of this document, smoke dampers Guide for Commissioning and Periodic Performance Testing of Fire, reduce the possibility of smoke transfer within ductwork or Smoke and Other Life Safety Related Dampers provides guidelines through wall openings. Activation of smoke dampers can be by from damper manufacturers on how to test dampers for ac- area detectors that are installed in the related smoke compart- ceptance testing and for follow-up periodic testing. ment or by detectors that are installed in the air duct systems. See NFPA 72, National Fire Alarm and Signaling Code. A.7.3.1 Generally, tests can be included with acceptance testing of the air-conditioning controls or fire alarm systems. A.6.3.4 Although permitted to remain open during fan shutdown, smoke dampers and combination fire and smoke dampers installed in smoke barriers should be arranged to close automatically when the fan system(s) they are serving is L Annex B Maintenance not in operation. This annex is not a part of the requirements of this NFPA document A.6.4 The use of smoke detectors in relationship to HVAC but is included for informational purposes only. systems and high air movement areas and the details regard- B.1 General. ing their optimum installation are covered in Section 5.7 of NFPA 72, National Fire Alarm and Signaling Code. B.1.1 Owners should develop a greater awareness of the life Protection provided by the installation of smoke detectors and property protection abilities of air-conditioning systems and related requirements is intended to prevent the distribu- and should establish a planned maintenance schedule. Fail- tion of smoke through the supply air duct system and, prefer- ure to maintain proper conditions of cleanliness in air duct ably, to exhaust a significant quantity of smoke to the outside. systems and carelessness in connection with repair operations Neither function, however, guarantees either the early detec- have been important contributing causes of several fires that tion of fire or the detection of smoke concentrations prior to have involved air-conditioning systems. The recommenda- dangerous smoke conditions where smoke movement is other tions in this annex apply, in general, to the period of opera- than through the supply air system. tion of the system; systems operating only part of the year Where smoke-control protection for a facility is deter- should be given a thorough general checkup before starting mined to be needed, see NFPA 92, Standard for Smoke Control operation and again after a shutdown. Systems. B.1.2 The intervals of testing and maintenance vary widely, depending on the duration of system operation, condition of A.6.4.2 The summation of the capacities of individual supply- fresh air, amount of dust in return air, and other factors. The air fans should be made where such fans are connected to a intervals specified in this standard are intended to be the common supply air duct system (i.e., all fans connected to a maximum and should be shortened if system conditions war- common air duct supply system should be considered as con- rant. stituting a single system with respect to the applicability of the Chapter 6 provisions that are dependent on system capacity). B.1.3 The use of an inspection form to obtain a thorough inspection is recommended. The form should fit the system or A.6.4.3 Where automatic water sprinklers are provided and systems involved, listing the items needing attention. How- zoned to coordinate with the HVAC zones, their water flow ever, it is recommended that provision be made on the form switches should initiate devices for the functions described in for equipment location, inspection frequency, due date, in- Chapter 6. spection date, inspector, and record of discrepancies found. Sprinklers are often tested weekly. Where it is desirable to prevent the accompanying automatic shutdown of the fan sys- B.2 Fire Dampers, Smoke Dampers, and Ceiling Dampers. tem(s) referred to in 6.4.3, a means can be permitted to be B.2.1 Refer to NFPA 80, Standard for Fire Doors and Other Open- used to avoid such shutdown temporarily, provided one of the ing Protectives, for inspection and maintenance of fire dampers, following occurs: ceiling dampers, and combination fire/smoke dampers. (1) A trouble signal is sustained in the sprinkler supervisory B.2.2 Refer to NFPA105, Standard for Smoke DoorAssemblies and system until the automatic shutdown provision is re- Other Opening Protectives, for inspection and maintenance of stored. smoke dampers and combination fire/smoke dampers. (2) The automatic shutdown provision is restored at the end of the time period necessary to test the sprinkler system, B.2.3 Refer to NFPA 92, Standard for Smoke Control Systems, for its alarms, and related elements. maintenance of smoke and combination fire/smoke dampers for each damper installed as part of a smoke control system. A.7.1.1 Many of the fire protection measures required in this B.3 Filters. standard are passive and function only in emergencies. There- fore, acceptance testing needs to be performed so that all B.3.1 All air filters should be kept free of excess dust and parts of air-conditioning systems are ready for a fire emer- combustible material. Unit filters should be renewed or

2015 Edition 90A–22 INSTALLATION OF AIR-CONDITIONING AND VENTILATING SYSTEMS cleaned when the resistance to airflow has increased to two B.7 Outside Air Intakes. times the original resistance or when the resistance has B.7.1 Conditions outside the outside air intake should be reached a value of recommended replacement by the manu- examined at the time ducts are inspected. Items to be noted facturer. A suitable draft gauge should be provided for the include the following: purpose. Where the filters are of the automatic liquid adhesive type, sludge should be removed from the liquid adhesive res- (1) Accumulations of combustible material near the intake ervoir regularly. (2) The presence of buildings or structures that could B.3.2 When filters are replaced, care should be taken to use present an exposure to the intake, allowing smoke and the proper type and size and to avoid gaps between filter sec- fire to be drawn in tions, mounting frames, or hardware. Damaged filter sections (3) The operating condition of any automatic damper de- or media should not be used. signed to protect the opening against exposure fire B.3.3 Filters designed and manufactured to be thrown away B.7.2 Where accumulations of combustible material are noted, after use should never be cleaned and reused. they should be removed immediately and arrangements made to avoid such accumulations. Inspections thereafter should be B.3.4 Care should be exercised in the use of liquid adhesives. made more frequently. If newly erected exposures are noticed, Use of an adhesive with a low flash point creates a serious consideration should be given to the protection at the intake to hazard. ensure that it is adequate. (See 4.3.7.) B.3.5 Electrical equipment of automatic filters should be in- B.8 Fans and Fan Motors. spected semiannually and the operation cycle observed to ensure that the motor, relays, and other controls function as in- B.8.1 Fans and fan motors should be inspected at least quar- tended. Drive motors and gear reductions also should be terly and cleaned and lubricated when necessary. Care should inspected at least semiannually and lubricated when neces- be exercised in lubricating fans to prevent lubricant from run- sary. ning onto the fan blades. Fans also should be checked for alignment and checked to see that they are running freely. B.4 Inspection and Cleaning of Ducts. B.8.2 The alignment of fan belt drives should be checked, B.4.1 Inspections to determine the amount of dust and waste because improper alignment can cause motor overheating as material in the ducts (both discharge and return) should be well as premature belt failure. made quarterly. If, after several inspections, such frequent inspection is determined to be unnecessary, the interval be- B.9 Controls. Fan controls should be examined and activated tween inspections can be permitted to be adjusted to suit the at least annually to ensure that they are in operable condition. conditions. B.4.2 Cleaning should be undertaken whenever an inspection indicates the need. L Annex C Informational References B.4.3 Cooling and heating coils should be cleaned, if necessary, at the time ducts are cleaned. Thorough cleaning of C.1 Referenced Publications. The documents or portions ducts can require scraping, brushing, or other positive means. thereof listed in this annex are referenced within the informa- Vacuum cleaning might not remove dust of an oily or sticky tional sections of this standard and are not part of the require- nature or heavy accumulations in the elbows or seams. The ments of this document unless also listed in Chapter 2 for amount and kind of dust and dirt depend greatly on the occu- other reasons. pancy and the arrangement of the duct system. Additional ac- C.1.1 NFPA Publications. National Fire Protection Associa- cess doors or panels could be needed to allow complete clean- tion, 1 Batterymarch Park, Quincy, MA 02169-7471. ing of duct systems. NFPA 31, Standard for the Installation of Oil-Burning Equip- B.5 Inspection and Cleaning of Plenums. ment, 2011 edition. NFPA 33, Standard for Spray Application Using Flammable or B.5.1 Apparatus casing and air-handling unit plenums Combustible Materials, 2011 edition. should be inspected monthly. If, after several inspections, such NFPA 34, Standard for Dipping, Coating, and Printing Processes frequent inspection is determined to be unnecessary, the in- Using Flammable or Combustible Liquids, 2011 edition. terval between inspections can be adjusted to suit the condi- NFPA 45, Standard on Fire Protection for Laboratories Using tions. Chemicals, 2011 edition. B.5.2 Ceiling cavity plenums, raised floor plenums, and duct NFPA 70®, National Electrical Code®, 2014 edition. distribution plenums should be inspected in a manner similar NFPA 72®, National Fire Alarm and Signaling Code, 2013 edi- to that of ducts, beginning with quarterly inspections and ad- tion. justing the frequency to suit dirt buildup conditions. NFPA 75, Standard for the Fire Protection of Information Technol- B.5.3 Cleaning should be undertaken whenever an inspec- ogy Equipment, 2013 edition. tion indicates the need, especially in common plenums NFPA 80, Standard for Fire Doors and Other Opening Protectives, serving more than one fan or system. Where plenum cham- 2013 edition. bers could be used for storage, arrangements, such as keep- NFPA 90B, Standard for the Installation of Warm Air Heating ing the doors locked, should be made to prevent such us- and Air-Conditioning Systems, 2015 edition. age. (See 4.3.10.) NFPA 91, Standard for Exhaust Systems for Air Conveying of B.6 Repair Work. Extreme caution should be exercised in the Vapors, Gases, Mists, and Noncombustible Particulate Solids, 2010 use of open flames or spark-emitting devices inside ducts or edition. plenum chambers or near air intakes. NFPA 92, Standard for Smoke Control Systems, 2012 edition.

2015 Edition ANNEX C 90A–23

NFPA 96, Standard for Ventilation Control and Fire Protection of ASTM E 2652, Standard Test Method for Behavior of Materials Commercial Cooking Operations, 2014 edition. in a Tube Furnace with a Cone-Shaped Airflow Stabilizer, at 750°C, NFPA 101®, Life Safety Code®, 2015 edition. 2012. NFPA 105, Standard for Smoke Door Assemblies and Other Open- C.1.2.4 NAIMA Publications. North American Insulation ing Protectives, 2013 edition. Manufacturers Association, 44 Canal Center Plaza, Suite 310, NFPA 220, Standard on Types of Building Construction, 2015 Alexandria, VA 22314. edition. Fibrous Glass Duct Liner Standard, 3rd edition, 2002. NFPA 259, Standard Test Method for Potential Heat of Building Fibrous Glass Duct Construction Standards, 5th edition, 2002. Materials, 2013 edition. NFPA 262, Standard Method of Test for Flame Travel and Smoke C.1.2.5 SMACNA Publications. Sheet Metal and Air- of Wires and Cables for Use in Air-Handling Spaces, 2011 edition. Conditioning Contractors’ National Association, Inc., 4201 Lafayette Center Drive, Chantilly, VA 22021-1209. C.1.2 Other Publications. Fire, Smoke and Radiation Damper Installation Guide for HVAC C.1.2.1 ASHRAE Publications. American Society of Heating, Systems, 2002. Refrigerating, and Air-Conditioning Engineers, Inc., 1791 Tul- C.1.2.6 UL Publications. Underwriters Laboratories Inc., 333 lie Circle, NE, Atlanta, GA 30329-2305. Pfingsten Road, Northbrook, IL 60062-2096. ANSI/ASHRAE/ASHE Standard 170, Ventilation of Health ANSI/UL 555, Standard for Safety Fire Dampers, 2006, Revised Care Facilities, 2008, with approved addendum. 2012. ASHRAE Handbook — Fundamentals, 2009. ANSI/UL 555S, Standard for Safety Smoke Dampers, 1999, Re- C.1.2.2 AMCA Publications. Air Movement and Control Asso- vised 2012. ciation (AMCA), 30 West University Drive, Arlington Heights, ANSI/UL 1565, Positioning Devices, 2002, Revised 2008. IL 60004. ANSI/UL 2043, Standard for Fire Test for Heat and Visible Guide for Commissioning and Periodic Performance Testing of Smoke Release for Discrete Products and Their Accessories Installed in Fire, Smoke and Other Life Safety Related Dampers, 2011. Air-Handling Spaces, 2008. C.1.2.3 ASTM International Publications. ASTM Interna- UL Subject 2424, Outline of Investigation for Cable Marked tional, 100 Barr Harbor Drive, P.O. Box C700, West Consho- Limited Combustible, 2006. hocken, PA 19428-2959. Building Materials Directory, 2012. ASTM E 84, Standard Test Method for Surface Burning Charac- Fire Resistance Directory, 2012. teristics of Building Materials, 2013a. Heating, Cooling, Ventilating and Cooking Equipment Directory, ASTM E 136, Standard Test Method for Behavior of Materials in 2012. a Vertical Tube Furnace at 750°C, 2012. C.2 Informational References. (Reserved) ASTM E 2231, Standard Practice for Specimen Preparation and Mounting of Pipe and Duct Insulation Materials to Assess Surface C.3 References for Extracts in Informational Sections. (Re- Burning Characteristics, 2009. served)

2015 Edition 90A–24 INSTALLATION OF AIR-CONDITIONING AND VENTILATING SYSTEMS

Index

Copyright © 2014 National Fire Protection Association. All Rights Reserved. The copyright in this index is separate and distinct from the copyright in the document that it indexes. The licensing provisions set forth for the document are not applicable to this index. This index may not be reproduced in whole or in part by any means without the express written permission of NFPA.

-A- Smoke Damper Acceptance Testing...... Chap. 7 Definition ...... 3.3.14.4, A.3.3.14.4 Controls and Operating Systems ...... 7.3 Definitions ...... Chap. 3 Fire Dampers, Smoke Dampers, and Ceiling Dampers ... 7.2, A.7.2 General ...... 7.1 -E- Accessible Definition...... 3.3.1 Environmental Air Administration...... Chap. 1 Definition ...... 3.3.15 Application ...... 1.3 Explanatory Material...... Annex A Equivalency...... 1.5 Purpose ...... 1.2 -F- Retroactivity ...... 1.4 Fan Scope...... 1.1, A.1.1 Definition ...... 3.3.16 Air Cleaner Definition...... 3.3.2 Fire Resistance Rating Air Connector Definition...... 3.3.17, A.3.3.17 Definition ...... 3.3.3, A.3.3.3 Fire Wall Air Distribution System Definition ...... 3.3.18 Definition...... 3.3.4 Flame Spread Index Air Duct Definition...... 3.3.19, A.3.3.19 Definition...... 3.3.5 Foam Plastic Insulation Air Duct Covering Definition ...... 3.3.20 Definition...... 3.3.6 Air Duct Lining -H- Definition...... 3.3.7 HVAC Systems ...... Chap. 4 Air Filter Definition...... 3.3.8 Air Distribution ...... 4.3, A.4.3 Air Inlet Air Connectors ...... 4.3.2 Definition ...... 3.3.9, A.3.3.9 Air Duct Access and Inspection...... 4.3.5 Air Outlet Air Duct Integrity ...... 4.3.6 Definition...... 3.3.10, A.3.3.10 Air Ducts...... 4.3.1 Air Terminal Unit Air Dispersion Systems ...... 4.3.1.8 Definition ...... 3.3.11 Gypsum Board Air Ducts ...... 4.3.1.3 Air Transfer Opening Air Inlets — Return or Exhaust or Return and Exhaust .... 4.3.8 Definition ...... 3.3.12 Construction of Air Inlets ...... 4.3.8.2 Approved General ...... 4.3.8.1 Definition ...... 3.2.1, A.3.2.1 Location of Air Inlets...... 4.3.8.3 Authority Having Jurisdiction (AHJ) Air Outlets...... 4.3.7 Definition ...... 3.2.2, A.3.2.2 Construction of Air Outlets ...... 4.3.7.2 General ...... 4.3.7.1 -C- Location of Air Outlets...... 4.3.7.3 Continued Progressive Combustion Corridor Air Systems ...... 4.3.12 Definition ...... 3.3.13 Egress Corridors...... 4.3.12.1 Controls ...... Chap. 6 Exits...... 4.3.12.2 Manual Control ...... 6.2 Fire Dampers...... 4.3.9 Smoke Dampers ...... 6.3, A.6.3 Materials for Operation and Control Smoke Detection for Automatic Control ...... 6.4, A.6.4 of the Air Distribution System ...... 4.3.4 Function...... 6.4.3, A.6.4.3 Plenums ...... 4.3.11 Installation ...... 6.4.4 Air-Handling Unit Room Plenum ...... 4.3.11.4 Location ...... 6.4.2, A.6.4.2 Apparatus Casing Plenum ...... 4.3.11.3 Testing ...... 6.4.1 Ceiling Cavity Plenum ...... 4.3.11.2 Wiring...... 6.1 Raised Floor Plenum ...... 4.3.11.5 Storage ...... 4.3.11.1 -D- Wall or Ceiling Finish in Plenums ...... 4.3.11.6 Damper Smoke Control ...... 4.3.13, A.4.3.13 Ceiling Damper Smoke Dampers ...... 4.3.10 Definition ...... 3.3.14.1, A.3.3.14.1 Supplementary Materials for Air Distribution Systems ...... 4.3.3 Combination Fire and Smoke Damper General Requirements for Equipment ...... 4.1 Definition ...... 3.3.14.2 Access ...... 4.1.1 Definition ...... 3.3.14 Protection ...... 4.1.3 Fire Damper Materials ...... 4.4 Definition ...... 3.3.14.3, A.3.3.14.3 Limited-Combustible Material ...... 4.4.2, A.4.4.2

2015 Edition INDEX 90A–25

Noncombustible Material...... 4.4.1, A.4.4.1 -L- System Components ...... 4.2 Limited-Combustible (Material) Air Cleaners and Air Filters ...... 4.2.2 Definition...... 3.3.21, A.3.3.21 Air-Cooling and Heating Equipment ...... 4.2.4 Listed Duct Heaters ...... 4.2.4.5 Definition ...... 3.2.3, A.3.2.3 Evaporative Coolers ...... 4.2.4.6 Furnaces ...... 4.2.4.4 -M- Heat Recovery Equipment ...... 4.2.4.7 Maintenance ...... Annex B Installation ...... 4.2.4.1 Materials ...... 4.2.4.2 Mechanical Cooling ...... 4.2.4.3 -N- Fans ...... 4.2.3 Noncombustible Material Access ...... 4.2.3.2 Definition...... 3.3.22, A.3.3.22 Exposed Inlets ...... 4.2.3.3 Installation ...... 4.2.3.1 -P- Outside Air Intakes ...... 4.2.1 Plenum Air-Handling Unit Room Plenum -I- Definition ...... 3.3.23.1 Apparatus Casing Plenum Informational References ...... Annex C Definition ...... 3.3.23.2 Integration of a Ventilation and Air-Conditioning Ceiling Cavity Plenum System(s) with Building Construction ...... Chap. 5 Definition ...... 3.3.23.3 Air-Handling Equipment Rooms ...... 5.1 Definition...... 3.3.23, A.3.3.23 Air-Handling Equipment Rooms That Raised Floor Plenum Have Air Ducts That Open Directly into a Shaft .... 5.1.3 Definition ...... 3.3.23.4 Air-Handling Equipment Rooms Used as Plenum Space ...... 5.1.2 -R- General ...... 5.1.1 Referenced Publications...... Chap. 2 Other Spaces Housing Air-Handling Units...... 5.1.4 General ...... 2.1 Building Construction...... 5.2 NFPA Publications ...... 2.2 Air Duct Clearance ...... 5.2.1 Other Publications...... 2.3 Ceiling Assemblies ...... 5.2.3 References for Extracts in Mandatory Sections ...... 2.4 Structural Members ...... 5.2.2 Fire Dampers, Smoke Dampers, and Ceiling Dampers ...... 5.4 -S- Ceiling Dampers ...... 5.4.4 Damper Closure ...... 5.4.5 Shall Fusible Links ...... 5.4.5.2 Definition...... 3.2.4 Should Damper Location Information ...... 5.4.6 Definition...... 3.2.5 Fire Dampers...... 5.4.1 Smoke Installation ...... 5.4.7 Definition ...... 3.3.24 Maintenance ...... 5.4.8 Smoke Barrier Smoke Dampers ...... 5.4.3, A.5.4.3 Definition...... 3.3.25, A.3.3.25 Penetrations — Protection of Openings ...... 5.3, A.5.3 Smoke Control Fire-Rated Walls and Partitions ...... 5.3.1 Definition ...... 3.3.26 Floor-Ceiling or Roof-Ceiling Smoke Detector Assemblies Having a Definition...... 3.3.27, A.3.3.27 Fire Resistance Rating...... 5.3.3, A.5.3.3 Smoke Developed Index Floors Required to Have a Fire Resistance Rating ...... 5.3.2 Definition...... 3.3.28, A.3.3.28 Shafts...... 5.3.4 Standard Smoke Barriers...... 5.3.5 Definition...... 3.2.6

Cou/W123456 17161514 2015 Edition Formal Interpretation

NFPA 90A Standard for the Installation of Air-Conditioning and Ventilating Systems

2015 Edition

Reference: 4.3.12.1 F.I. No.: 90A-02-04

Question No. 1: Is the intent of the paragraph to require multiple locations for return air in a corridor?

Answer: No.

Question No. 2: Is one point of return air with multiple supply air locations as indicated on the attached sketch acceptable?

Answer: Yes.

Issue Edition: 2002 Reference: 4.3.11.1 Issue Date: 12/19/2007 Effective Date: 1/8/2008

NFPA 90A Standard for the Installation of Air-Conditioning and Ventilating Systems

2015 Edition

Reference: 4.3.12.1, 3.3.5 and 3.3.22 F.I. No. 90A-02-3

Question 1: When the resident’s room windows are closed, can the 50cfr of air exhausted from the bathroom and drawn from the room in general be in whole or in part made up by infiltration through the NFPA 80 complying clearances around and under the corridor door due to the resultant pressure differences?

Answer: Yes.

Question 2: Does the corridor described constitute a plenum or air duct as these terms were intended to apply under 90A?

Answer: No.

Issue Edition: 2002 Reference: 4.3.11.1, 3.3.5 and 3.3.21 Issue Date: January 24, 2006 Effective Date: February 12, 2006

NFPA 90A

Standard for the Installation of Air-Conditioning and Ventilating Systems

2015 Edition

Reference: 5.3.4.5 FI No. 90A-02-02

Question: Is it the intent of NFPA 90A: 5.3.4.5 to prohibit the installation of a Type B vent, which is connected to and exhausts a natural gas fire boiler within an environmental air shaft?

Answer: Yes.

Issue Edition: 2002 Reference: 5.3.4.5 Issue Date: January 10, 2006 Effective Date: January 30, 2006

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VI. Step 3b: Documents Forwarded Directly to the Council. Where no Notice of Intent to Make a Motion (NITMAM) is received and certified in accordance with the Technical Meeting Convention Rules, the standard is forwarded directly to the Standards Council for action on issuance. Objections are deemed to be resolved for these documents. (See Regs at 4.5.2.5)

VII. Step 4a: Council Appeals. Anyone can appeal to the Standards Council concerning procedural or substantive matters related to the development, content, or issuance of any document of the Association or on matters within the purview of the authority of the Council, as established by the Bylaws and as determined by the Board of Directors. Such appeals must be in written form and filed with the Secretary of the Standards Council (See Regs at 1.6). Time constraints for filing an appeal must be in accordance with 1.6.2 of the Regs. Objections are deemed to be resolved if not pursued at this level.

VIII. Step 4b: Document Issuance. The Standards Council is the issuer of all documents (see Article 8 of Bylaws). The Council acts on the issuance of a document presented for action at an Association Technical Meeting within 75 days from the date of the recommendation from the Association Technical Meeting, unless this period is extended by the Council (See Regs at 4.7.2). For documents forwarded directly to the Standards Council, the Council acts on the issuance of the document at its next scheduled meeting, or at such other meeting as the Council may determine (See Regs at 4.5.2.5 and 4.7.4).

IX. Petitions to the Board of Directors. The Standards Council has been delegated the responsibility for the administration of the codes and standards development process and the issuance of documents. However, where extraordinary circumstances requiring the intervention of the Board of Directors exist, the Board of Directors may take any action necessary to fulfill its obligations to preserve the integrity of the codes and standards development process and to protect the interests of the Association. The rules for petitioning the Board of Directors can be found in the Regulations Governing Petitions to the Board of Directors from Decisions of the Standards Council and in 1.7 of the Regs.

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12/12-E NFPA 90A Standard for the Installation of Air-Conditioning and Ventilating Systems Handbook 2015

ORIGIN AND DEVELOPMENT

As early as 1899, the National Fire Protection Association (NFPA) recognized the fire hazard of blower and exhaust systems as a source of fire or a means of spreading fire. Blower systems, which were often an economic necessity, usually introduced an additional hazard contributing to the cause and spread of fire, particularly when used for conveying stock and refuse. It was and is impossible to eliminate the fire hazard from such systems, but reasonable safeguards can be provided to reduce it. Reports of the NFPA Committee on Blower Systems presented in 1900 and 1901 outlined the initial methods for safeguarding against this hazard. With the use of blower and exhaust systems increasing, the need for a more detailed standard for the installation of these systems became apparent, and work was started in 1913 that resulted in the adoption of the first edition of the standard in 1915. Since that time each and every committee has given a great deal of attention to the subject, and revisions have been made at frequent intervals to meet new experiences and new techno- logical advances. In 1924 a complete new section was added to cover systems for the removal of flammable vapors. Further amendments were made in 1932 and 1933, and the standard was approved as an American Standard by the American Standards Association on January 31, 1935. With the widespread introduction of air conditioning in the 1930s, more changes became necessary to make the regulations specifically applicable to air-conditioning installations. They had been previously covered in principle, but now there were certain details that required a more specific treatment. Those revisions were made in 1936, and the title was revised to “Regu- lations for the Installation of Power Operated Ventilating, Air Conditioning, Dust, Stock and Va- por Removal Systems” to clarify the new scope. The continuing rapid development of air-conditioning technology lead to the 1937 decision to split the criteria into two separate regulations, one dealing with air-conditioning, heating, and ventilating systems, and the other with systems for the removal of flammable dusts, vapors, and so on. Fire experience in 1938 indicated the need for further changes in the air-conditioning regulations in order to keep pace with current developing experience and included the addition of an appendix on maintenance. Prior to 1964, the document required that “ducts shall be constructed entirely of noncombustible material such as iron, steel, aluminum or other approved material.” Any attic, basement, or concealed space used as part of a duct system had to conform to all the requirements for ducts, and it had to be approved by the authority having jurisdiction. The use of these “non- duct” spaces to move environmental air significantly changed the construction requirements for these spaces in a manner very similar to what is done for changing occupancies. In 1964, changes were made to allow the use of attics, basements, or concealed spaces, called plenums, to be used to move environmental air (air breathed by occupants). However, those spaces could not be used as part of the supply or return system through required exit corridors in multi-family houses, hotels, hospitals, institutions, and similar occupancies. Stairways connecting two or more stories could not be used as plenums either. There were still considerable concerns for fire and life safety and so, even where the use of plenums was allowed, quite a number of conditions needed to be met first, including the basic requirement that the floor and ceiling construction had to have fire-resisting ceilings of not less than a 1 hour fire resistance rating when tested in accordance with NFPA 251, Standard Methods of Fire Tests of Building Construction. In 1968, the committee allowed the relatively new technology of smoke detectors to be used as an alternative method to heat detectors to shut down air-handling units larger than 15,000 cubic feet per minute. In 1981, the committee discontinued allowing the use of heat detectors and required smoke detectors to be installed to shut down all HVAC units when the aggregate cubic feet per minute of units connected to a common duct exceeded 2000 cubic feet per minute. Today, although containing only 13 pages of technical requirements, this document applies to the vast majority of commercial buildings in this country as well as many high-rise multiple dwelling unit buildings, as they use forced air systems for heating and/or cooling.

NFPA 90A 2015 Handbook Edition NFPA 90A Standard for the Installation of Air-Conditioning and Ventilating Systems Handbook 2015

This document is unique among model codes and standards for two reasons: 1 It allows for the connection of horizontal and vertical concealed spaces that are not allowed by other model codes and standards under certain specific conditions. 2 It allows horizontal and vertical concealed spaces that were not built for a specific purpose and do not “belong” to any specific trade, but are simply spaces naturally created in the construction process, to provide some cost saving construction applications by permitting environmental air to be moved through them when specific requirements are met. Chapter 1 The information found in Chapter 1 is essential for establishing a framework for using and ap- plying the standard. The authority having jurisdiction (AHJ) needs to understand the boundar- ies of the document in order to administer the provisions and to avoid conflicts and overlaps with other codes or standards that may have been adopted. Chapter 1 includes the following administrative topics: • Scope (Section 1.1) • Purpose (Section 1.2) • Application (Section 1.3) • Retroactivity (Section 1.4) • Equivalency (Section 1.5) These sections lay the ground rules by which the standard is enforced. These rules are necessary in order to achieve uniformity in enforcement between jurisdictions, which assists the users of the standard in complying with its provisions. Chapter 1 is the starting point of the standard. The user of any standard must first determine its applicability to his or her situation. Without concern for the document’s scope or purpose, it is impossible to determine proper compliance. Chapter 1 provides the necessary information to determine whether the standard applies to an installation. 1.1 The document scope describes in general terms what the document covers, and includes sufficient details to explain the range or limits of what is covered. 1.2 All NFPA codes and standards are required to contain a document purpose section that describes the goal of the document. The document purpose also describes the objective(s) of the document or what it was created to accomplish. 1.3 Most NFPA codes and standards contain an application section that indicates how and to what the requirements of the document apply. The technical committee has specifically limited the application of requirements for environmental air-handling systems in this document to only those systems within the buildings and spaces in the numbered list. The Annex A notes help to clarify what the committee intended with the list. 1.4 Section 1.4 clearly states that the requirements cannot be applied to existing buildings where no work is being done. However, they will apply to any work done beyond repairs to those systems in the future. This provision is based upon, and consistent with, the various court cases that have ruled that as long as an existing structure complied with the adopted codes at the time of construction, updates or changes cannot be required unless work is done on the system. 1.5 Section 1.5 provides the opportunity for the applicant to propose the use of a method or material that is different from those specifically required or allowed in the standard by providing

NFPA 90A 2015 Handbook Edition NFPA 90A Standard for the Installation of Air-Conditioning and Ventilating Systems Handbook 2015

sufficient documentation that such method or material will provide the same level of performance as the required method or material. It must be noted that there is no requirement that the authority having jurisdiction (AHJ) must allow the alternative under any circumstances. It is therefore wise to discuss with the AHJ whether or not the AHJ may even consider such a process before spending any time or money on it. The AHJ does not have to approve any alternatives, no matter how well they may be supported. Chapter 2 This chapter lists the mandatory publications referenced within NFPA 90A, while Annex C lists non-mandatory publications referenced within informational sections of the standard. By lo- cating the information immediately after Chapter 1, Administration, the user is presented with the complete list of publications needed for effective use of the standard before reading the specific requirements. Chapter 3 Chapter 3 contains official NFPA definitions and “General Definitions,” which are technical terms whose definitions are considered crucial to the proper understanding of NFPA 90A. For both the user and the authority having jurisdiction (AHJ) to speak the same language when discussing a requirement, they must know the intended meaning of a word. Although these terms may be used or defined differently in another standard, these definitions are the only ones that apply within the scope of this standard. 3.1 This section provides general information about the definitions used in this document. It also advises the user that should a term not be defined in this chapter, then the common definition found in Merriam-Webster’s Collegiate Dictionary will apply. 3.2 Official NFPA definitions are the same in all NFPA documents. Many NFPA documents rely on or cross-reference each other, and thus having official definitions facilitates the consistency of the documents. 3.2.2 Although NFPA creates model codes and standards that may be adopted into law, it is the authority having jurisdiction (AHJ) that makes the final decision, subject to applicable appeals, as to what installation complies with the requirements found within the standard. Within their jurisdictions, the AHJs provide the primary official interpretation and determine the equivalency of a requirement. Any given project may have multiple jurisdictions with authority over some part(s) of the project. 3.2.3 All methods, systems, and devices under the scope of NFPA 90A are required to be approved. Listing is specified if necessary to comply with a requirement. Although a standard may not require the use of listed equipment, many authorities having jurisdiction (AHJs) will require listing of equipment in order to speed the approval process. Even when listing is not required, manufacturers often will have their equipment listed to facilitate its installation and approval. 3.3 The definitions in Section 3.3 are technical terms that are considered crucial to the proper understanding of this document. These definitions are applicable only within this specific standard. Although these terms may be used or defined differently in another standard, these definitions are the only ones that apply within the scope of this standard.

NFPA 90A 2015 Handbook Edition NFPA 90A Standard for the Installation of Air-Conditioning and Ventilating Systems Handbook 2015

3.3.4 Many designers, contractors, AHJs, and building owners miss the last seven (and critical) words of this definition. Occupied spaces are not part of the air distribution system and therefore are not covered in this document. The air distribution system runs from the point that the air leaves an occupied space until it is either exhausted out of the building or returned to an occupied space. 3.3.14.3 There are many different styles of fire dampers depending on manufacturer and situation, but Exhibit 1 is a good example of a typical one.

EXHIBIT 1 Simple Fire Damper with Fusible Link.

3.3.21 The interpretation of this term has been problematic over the years. It has also been the subject of two major decisions by the NFPA Standards Council. This term is only to be applied to materials defined and regulated in NFPA 220, Standard on Types of Building Construction. The Standards Council has twice directed all technical committees to remove the term from their documents unless it is used for those materials defined and regulated by NFPA 220. Therefore, the use of the term limited combustible cannot be applied to wire, cable, lights, ducts, supports, insulation, or any other material within an air distribution system for purposes of compliance with the requirements of NFPA 90A. 3.3.23 In NFPA 90A, “plenum” is a name that is only given to a concealed space when environmental air is moved through it. It is generally formed by the normal building construction, such as the space above a suspended ceiling or below a raised floor. That same space is not a plenum if environmental air is not moved through it. The committee added an Annex A note to clarify that there may be various names used with specific uses of plenums. Chapter 4 Chapter 4 describes all the various components, and the associated requirements for each individual component, that may be a part of any particular HVAC system.

NFPA 90A 2015 Handbook Edition NFPA 90A Standard for the Installation of Air-Conditioning and Ventilating Systems Handbook 2015

4.3.3 These are materials that are not necessary for the operation of the air distribution system, but NFPA 90A allows them to be within the air distribution system for the purposes of detecting smoke or fire, energy efficiency, wiring to power such devices, or some other purpose or function that the technical committee deems appropriate. NFPA 90A strictly limits the quantity and volume of such materials to minimize their potential fire hazard within the system. 4.3.5.1 NFPA 90A requires access doors for the maintenance of various items but does not specify a specific size or even a range of sizes, as practical access will vary so much from application to application. The technical committee expects that reasonable thought will be given to both the size of the opening and the path technicians will use to get to the opening. Being able to reach and work on a device within the system is more important than, for example, the distance a technician must walk or crawl to actually get to the access door itself. Exhibit 2 is a diagram from the 1939 edition that gives a clear example in graphic form of the “access” intended. There are two stages of access, in reverse order: (1) physically getting into the duct with enough room so that one can see and easily work and/or test the duct detector, and (2) getting from public space to where the access to the duct detector in (1) is provided. See Exhibits 2, 3, and 4.

EXHIBIT 2 Diagram Showing Access Door (Hand Hole). (Source: Figure 4A from NFPA 90A, 1939 edition)

NFPA 90A 2015 Handbook Edition NFPA 90A Standard for the Installation of Air-Conditioning and Ventilating Systems Handbook 2015

EXHIBIT 3 Fire Damper with Firestopping Around Unit.

EXHIBIT 4 Access Door for Fire Damper.

4.3.12.1.1 This is one of the more widely misunderstood and misinterpreted paragraphs of this standard. This provision prohibits environmental air from passing from an occupied space to an egress corridor or passing from an egress corridor to an occupied space before it passes through the air distribution system in the occupancies listed.

NFPA 90A 2015 Handbook Edition NFPA 90A Standard for the Installation of Air-Conditioning and Ventilating Systems Handbook 2015

As an example: One air handler serves the corridor and adjoining patient room. The supply is fully ducted to the corridor and the room. The room return is fully ducted, and the corridor return is via the plenum space over the corridor ceiling. There is a wastebasket fire in a patient room. The smoke from it would have to enter the return system directly from the room, where it would go back to the air handler and past the supply side smoke detector, thereby shutting down the unit before it could deliver the smoke-contaminated air back to the corridor. Conversely, there is a wastebasket fire in the corridor. The smoke from it would have to enter the return system plenum directly from the corridor, where it would go back to the air handler and past the supply side smoke detector, thereby shutting down the unit before it could deliver the smoke-contaminated air back to the patient room. The intent is to prohibit smoke-contaminated air moving, in either direction, directly from one occupied space (patient room) to another occupied space (corridor). The subparagraphs below are essentially exceptions to the requirement in 4.3.12.1.1. 4.3.12.1.3.1 Since these spaces do not, and should not, have combustible storage in them, there is virtu- ally no opportunity for smoke-contaminated air moving, in either direction, directly from these spaces to the corridor and causing a problem. 4.3.12.1.3.2 The amount of air transfer is minimal given the following tolerances (taken from NFPA 80, Stan- dard for Fire Doors and Other Opening Protectives), particularly under the door, where any smoke would have to entirely fill the space from ceiling to floor before any transfer would occur: • A maximum ¾ in. (19 mm) wood and composite door undercutting (NFPA 80, 2013 edition, 4.1.3.2) • The clearances between the top and vertical edges of the door and the frame, and the meeting edges of doors swinging in pairs, shall be 1⁄8 in. ± 1⁄16 in. (3.18 mm ± 1.59 mm) for steel doors and shall not exceed 1⁄8 in. (3.18 mm) for wood doors. (NFPA 80, 2013 edition, 6.3.1.7.1)

4.3.12.1.3.3 NFPA 90A allows design professionals to use corridors as a part of an engineered smoke control system designed and operated in accordance with NFPA 92, Standard for Smoke Control Systems. NFPA 92 sets minimum “tenability” requirements that are intended to ensure that an egress corridor remains usable for human evacuation without any special equipment for a prescribed period of time. The burden is on the engineer to prove to the AHJ that the system will perform in such a manner as to maintain the corridor tenability as an exit. 4.3.12.1.3.4 These occupancies, by their very nature, severely and intentionally, restrict the movement of occupants within the building. As part of that restriction other requirements for fire and life safety are put into place that, in the opinion of the committee, provide adequate assurance that those individuals whose movement is so restricted have adequate provisions and systems in place to protect them in fire and other life safety situations. Such provisions and systems include, but are not limited to, design, construction, and compartmentation; provision for detection, alarm, and extinguishment; fire prevention and planning, training, and drilling programs for the isolation of fire and the transfer of occupants to areas of refuge, for evacuation of the building, or for protection of the occupants in place. Chapter 5 Chapter 5 sets out the requirements that apply, over and above the requirements for the individual components in Chapter 4, to the complete system. 5.3.4.2 The requirement in 5.3.4.2 and a similar one in 5.3.4.3 are often misunderstood by designers and contractors. The 1 hour rated wall must be between the duct and any other space, occupied

NFPA 90A 2015 Handbook Edition NFPA 90A Standard for the Installation of Air-Conditioning and Ventilating Systems Handbook 2015

or unoccupied (Exhibit 5). It does not mean that the duct is to be in the middle of a 1 hour wall (Exhibit 6).

1 hr assemblies

Vertical air distribution duct

Enclosing partition/wall

Shaft enclosure

EXHIBIT 5 Properly Constructed Shaft.

1 hour wall assembly

Vertical air distribution duct

EXHIBIT 6 Improperly Constructed Shaft.

NFPA 90A 2015 Handbook Edition NFPA 90A Standard for the Installation of Air-Conditioning and Ventilating Systems Handbook 2015

5.3.4.5 NFPA 90A prohibits ducts and pipes that carry materials that could contaminate the air we breathe (environmental air) from being enclosed within the same shaft that encloses ducts moving environmental air. It also prohibits combustible materials including, but not limited to, the storage of combustible material or the passage of combustible material including, but not limited to, rubbish (refuse chutes) and clothing (laundry chutes) from being in the same shafts that move environmental air. 5.3.4.6 Fire dampers prevent fire from getting into a shaft and traveling to another floor. There are some instances where the committee does not require dampers, as the possibility of fire transfer is very remote. See 5.3.4.6.1 and 5.3.4.6.2. 5.3.4.6.1 In this instance, the shaft is effectively an extension of the same floor as it is separated from all other floors and has no penetrations or openings. 5.3.4.6.2 In these cases, the subducts, by virtue of their construction and design, prevent fire from spreading to other floors, and so the technical committee does not see the need for dampers. The steel will resist a fire, and the physics of fire combined with upturn does not allow a fire to reverse direction and travel downward. 5.4.8.1 Both NFPA 80 and NFPA 90A require dampers to be able to function at all times. Exhibit 7 is one example of improperly interfering with a damper’s operation.

EXHIBIT 7 Fire Damper Improperly Blocked Open.

NFPA 90A 2015 Handbook Edition NFPA 90A Standard for the Installation of Air-Conditioning and Ventilating Systems Handbook 2015

Chapter 6 Chapter 6 covers the operation, functions, controls, and locations of certain dampers and smoke detectors in or attached to the HVAC system. It also specifies the periodic testing of all devices that provide automatic closing of dampers and the automatic shutdown of units. 6.3.1 Exhibit 8 is a good example of what an “alarm-initiated” damper might look like.

EXHIBIT 8 Round Combination Fire/Smoke Motorized Damper.

6.4.1 All smoke detectors required in 6.4.2 are required to be tested yearly to ensure that they do, in fact, shut down their respective air handlers. 6.4.2.1(1) The purpose of these smoke detectors is to shut down the air handler (fan) of the single unit it is serving in the event of a fire or smoke from the motor, filter, belts, and so on, of that unit. The fire load from those items is small and will likely burn out long before first responders can arrive. In addition, the amount of smoke generated will likely not migrate out of the system once the fan is shut down. Hence, there is no requirement to sound an evacuation alarm because an evacuation is more likely to cause problems than the small amount of smoke. 6.4.2.2 There are two purposes for smoke detectors on returns. The first is to shut down the air handler (fan) of the single unit it is serving in the event of a fire or smoke from the motor, filter, belts, and so on, of that unit and to close the smoke dampers required by 4.3.9.2 to contain smoke from a fire in the unit. The second is to provide shutdown where smoke might migrate from other floors through a common return prior to shutdown by the supply side detector. The committee considers area detection, and therefore a building alarm, sufficient for occupant safety so that the return side detector is not required where there is area detection.

NFPA 90A 2015 Handbook Edition NFPA 90A Standard for the Installation of Air-Conditioning and Ventilating Systems Handbook 2015

6.4.2.3 There are two purposes for smoke detectors on returns. The first is to shut down the air handler (fan) of the single unit it is serving in the event of a fire or smoke from the motor, filter, belts, and so on, of that unit and to close the smoke dampers required by 4.3.9.2 to contain smoke from a fire in the unit. The second is to provide shutdown where smoke might migrate from other floors through a common return prior to shutdown by the supply side detector. The committee considers area detection, and therefore a building alarm, sufficient for occupant safety so that the return side detector is not required where there is area detection. Chapter 7 Chapter 7 covers what testing and documentation of those tests are required prior to the occupancy of the building. Annex A Annex A is included solely to help the user of the document understand the intent of the requirements in the body of the standard by providing further explanatory text, figures, and tables. While the provisions in the body of the standard are mandatory, Annex A is non-mandatory material prepared and voted on by the technical committee. Although the information is processed the same way as mandatory requirements, the annex material is not enforceable. The committee generates this information to provide additional guidance not capable of being included within the mandatory requirements. Annex B Annex B provides guidance for building owners or their representatives in creating a maintenance, inspection, and testing plan for their buildings. Annex C This annex lists publications that are referenced within the standard’s non-mandatory annexes. Chapter 2 lists publications that are mandatory to the extent referenced within the mandatory body of the code. The publications in this annex are NOT mandatory but do contain information that can assist with the installation of emergency and standby power systems. This list is neither an exhaustive list nor an endorsement of the materials mentioned.

NFPA 90A 2015 Handbook Edition