ANSI/ASHRAE Standard 15-2013
`(Supersedes ANSI/ASHRAE Standard 15-2010)
`Includes ANSI/ASHRAE addenda listed in Appendix F
`
`Safety Standard for
`Refrigeration Systems
`
`See Appendix F for approval dates by the ASHRAE Standards Committee, the ASHRAE Board of Directors, and the American
`National Standards Institute.
`
`This standard is under continuous maintenance by a Standing Standard Project Committee (SSPC) for which the Standards Com-
`mittee has established a documented program for regular publication of addenda or revisions, including procedures for timely,
`documented, consensus action on requests for change to any part of the standard. The change submittal form, instructions, and
`deadlines may be obtained in electronic form from the ASHRAE website (www.ashrae.org) or in paper form from the Manager of
`Standards. The latest edition of an ASHRAE Standard may be purchased from the ASHRAE website (www.ashrae.org) or from
`ASHRAE Customer Service, 1791 Tullie Circle, NE, Atlanta, GA 30329-2305. E-mail: orders@ashrae.org. Fax: 678-539-2129.
`Telephone: 404-636-8400 (worldwide), or toll free 1-800-527-4723 (for orders in US and Canada). For reprint permission, go to
`www.ashrae.org/permissions.
`
`© 2013 ASHRAE ISSN 1041-2336
`
`p
`
`
`
`
`
`
`
`
`
`
`
`6
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
` N
`
` p
`
`
`
`b
`
` p
`
` D
`
`b
`
`
`
`
`
` b
`
`
`
`
`
`
`
`
`
`Arkema Exhibit 1110
`
`1 of 82
`
`

`
`ASHRAE Standing Standard Project Committee 15
`Cognizant TCs: TC 10.1, Custom Engineered Refrigeration Systems,
`and TC 9.1, Large Building Air-Conditioning Systems
`SPLS Liaison: Mark P. Modera
`Staff Liaison: Douglas K. Tucker
`
`Dennis R. Dorman, Chair
`Martin L. Timm, Vice Chair
`Gregory A. Scrivener, Secretary
`A. Bruce Badger
`Els Baert
`Wayne K. Borrowman
`James M. Calm
`Jim Caylor
`
`Paul L. Doppel
`Stephen W. Duda
`Danny M. Halel
`Phillip A. Johnson
`Jay A. Kohler
`C. Dominic Kolandayan
`Scott M. MacBain, Sr.
`Chun-cheng Piao
`
`ASHRAE STANDARDS COMMITTEE 2013–2014
`
`William F. Walter, Chair
`Richard L. Hall, Vice-Chair
`Karim Amrane
`Joseph R. Anderson
`James Dale Aswegan
`Charles S. Barnaby
`Steven F. Bruning
`John A. Clark
`Waller S. Clements
`
`David R. Conover
`John F. Dunlap
`James W. Earley, Jr.
`Steven J. Emmerich
`Julie M. Ferguson
`Krishnan Gowri
`Cecily M. Grzywacz
`Rita M. Harrold
`Adam W. Hinge
`Debra H. Kennoy
`
`Stephanie C. Reiniche, Manager of Standards
`
`Douglas T. Reindl
`Brian J. Rodgers
`Jeffrey M. Shapiro
`Eric M. Smith
`Ganesan Sundaresan
`Russell C. Tharp
`Ronald P. Vallort
`John I. Vucci
`Kyle D. Wessells
`
`Malcolm D. Knight
`Rick A. Larson
`Mark P. Modera
`Cyrus H. Nasseri
`Janice C. Peterson
`Heather L. Platt
`Douglas T. Reindl
`Julia A. Keen, BOD ExO
`Thomas E. Werkema, Jr., CO
`
`SPECIAL NOTE
`This American National Standard (ANS) is a national voluntary consensus standard developed under the auspices of ASHRAE.
`Consensus is defined by the American National Standards Institute (ANSI), of which ASHRAE is a member and which has approved this
`standard as an ANS, as “substantial agreement reached by directly and materially affected interest categories. This signifies the concurrence
`of more than a simple majority, but not necessarily unanimity. Consensus requires that all views and objections be considered, and that an
`effort be made toward their resolution.” Compliance with this standard is voluntary until and unless a legal jurisdiction makes compliance
`mandatory through legislation.
`ASHRAE obtains consensus through participation of its national and international members, associated societies, and public review.
`ASHRAE Standards are prepared by a Project Committee appointed specifically for the purpose of writing the Standard. The Project
`Committee Chair and Vice-Chair must be members of ASHRAE; while other committee members may or may not be ASHRAE members, all
`must be technically qualified in the subject area of the Standard. Every effort is made to balance the concerned interests on all Project
`Committees.
`The Manager of Standards of ASHRAE should be contacted for:
`a. interpretation of the contents of this Standard,
`b. participation in the next review of the Standard,
`c. offering constructive criticism for improving the Standard, or
`d. permission to reprint portions of the Standard.
`
`DISCLAIMER
`ASHRAE uses its best efforts to promulgate Standards and Guidelines for the benefit of the public in light of available information and
`accepted industry practices. However, ASHRAE does not guarantee, certify, or assure the safety or performance of any products, components,
`or systems tested, installed, or operated in accordance with ASHRAE’s Standards or Guidelines or that any tests conducted under its
`Standards or Guidelines will be nonhazardous or free from risk.
`
`ASHRAE INDUSTRIAL ADVERTISING POLICY ON STANDARDS
`ASHRAE Standards and Guidelines are established to assist industry and the public by offering a uniform method of testing for rating
`purposes, by suggesting safe practices in designing and installing equipment, by providing proper definitions of this equipment, and by providing
`other information that may serve to guide the industry. The creation of ASHRAE Standards and Guidelines is determined by the need for them,
`and conformance to them is completely voluntary.
`In referring to this Standard or Guideline and in marking of equipment and in advertising, no claim shall be made, either stated or implied,
`that the product has been approved by ASHRAE.
`
`© ASHRAE (www.ashrae.org). For personal use only. Additional reproduction, distribution,
`or transmission in either print or digital form is not permitted without ASHRAE's prior written permission.
`
`p
`
`
`
`
`
`
`
`
`
`
`
`6
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
` N
`
` p
`
`
`
`b
`
` p
`
` D
`
`b
`
`
`
`
`
` b
`
`
`
`
`
`
`
`
`
`2 of 82
`
`

`
`CONTENTS
`ANSI/ASHRAE Standard 15-2013,
`Safety Standard for Refrigeration Systems
`
`PAGE
`SECTION
`Foreword .....................................................................................................................................................................2
`1 Purpose.............................................................................................................................................................3
`2 Scope ................................................................................................................................................................3
`3 Definitions .........................................................................................................................................................3
`4 Occupancy Classification ..................................................................................................................................5
`5 Refrigerating System Classification ..................................................................................................................6
`6 Refrigerant Safety Classification .......................................................................................................................7
`7 Restrictions on Refrigerant Use ........................................................................................................................7
`8 Installation Restrictions .....................................................................................................................................9
`9 Design and Construction of Equipment and Systems.....................................................................................11
`10 Operation and Testing .....................................................................................................................................22
`11 General Requirements ....................................................................................................................................22
`12 Precedence with Conflicting Requirements.....................................................................................................23
`13 Listed Equipment.............................................................................................................................................23
`Informative Appendix A—Informative References ................................................................................................24
`
`Normative Appendix B—Normative References ...................................................................................................24
`
`Informative Appendix C—Method for Calculating Discharge Capacity of
`Positive Displacement Compressor Pressure-Relief Device .............................................................25
`
`Normative Appendix D—Allowable Equivalent Length of Discharge Piping .........................................................27
`
`Informative Appendix E—Emergencies in Refrigerating Machinery Rooms .........................................................28
`
`Informative Appendix F—Addenda Description Information .................................................................................30
`
`Approved addenda, errata, or interpretations for this standard can be downloaded free of charge from the ASHRAE
`Web site at www.ashrae.org/technology.
`
`NOTE
`
`© 2013 ASHRAE
`1791 Tullie Circle NE · Atlanta, GA 30329 · www.ashrae.org · All rights reserved.
`ASHRAE is a registered trademark of the American Society of Heating, Refrigerating and Air-Conditioning Engineers, Inc.
`ANSI is a registered trademark of the American National Standards Institute.
`
`© ASHRAE (www.ashrae.org). For personal use only. Additional reproduction, distribution,
`or transmission in either print or digital form is not permitted without ASHRAE's prior written permission.
`
`p
`
`
`
`
`
`
`
`
`
`
`
`6
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
` N
`
` p
`
`
`
`b
`
` p
`
` D
`
`b
`
`
`
`
`
` b
`
`
`
`
`
`
`
`
`
`3 of 82
`
`

`
`(This foreword is not part of this standard. It is merely
`informative and does not contain requirements necessary
`for conformance to the standard. It has not been pro-
`cessed according to the ANSI requirements for a standard
`and may contain material that has not been subject to
`public review or a consensus process. Unresolved objec-
`tors on informative material are not offered the right to
`appeal at ASHRAE or ANSI.)
`
`FOREWORD
`ASHRAE Standard 15-2013 is the most recent edition of
`one of ASHRAE’s oldest standards. Standard 15 is under con-
`tinuous maintenance, which means it is modified and updated
`based on feedback from users, changes in the science originat-
`ing from ASHRAE and industry research, and industry changes
`that respond to the global interest in improved environmental
`responsibility. Interested parties can recommend changes to the
`standard by submitting a change proposal using the continuous
`maintenance form included in the back of the standard. Stan-
`dard 15-2013 includes all of the published addenda to the 2010
`version as shown in Informative Appendix F.
`ASHRAE Standard 15 must be used with its sister stan-
`dard, ANSI/ASHRAE Standard 34, Designation and Safety
`Classification of Refrigerants.1 Standard 34 prescribes the
`Refrigerant Classification System, as well as refrigerant con-
`centration limits (RCL), that are vitally important in applying
`this standard. Although changes to Standard 15 are closely
`coordinated with those to Standard 34, users of Standard 15
`should also review the most recent version of Standard 34 and
`its associated addenda for the latest information related to
`refrigerant designations and safety classifications.
`ASHRAE Standard 15 gives a method for determining the
`amount of refrigerant in a given space that, when exceeded,
`requires a machinery room. When a refrigerant is not classi-
`fied in ASHRAE Standard 34 or its addenda, it is the respon-
`sibility of the owner of a refrigerating system to make this
`judgment.
`Users of ASHRAE Standard 15 may also find it useful to
`refer to the Standard 15-2001 User’s Manual. The user’s man-
`ual was developed as a companion document to ASHRAE
`Standard 15. Though it does not reflect the addenda and
`changes incorporated into Standard 15 since its original pub-
`lication, it still serves to clarify the intent of the standard and
`provides an explanation of the rationale behind its creation.
`Its purpose is to assist in use of the standard by including
`illustrations and examples of accepted industry practice, as
`well as explanations of and supporting references for formu-
`las in the standard. The user’s manual also covers building,
`system, and refrigerant classifications, restrictions on refrig-
`erant use, installation restrictions, and equipment and system
`design and construction for commercial, residential, and
`industrial applications.
`ASHRAE Standard 15 is directed toward the safety of
`persons and property on or near the premises where refriger-
`ation facilities are located. It includes specifications for fabri-
`cation of refrigerating systems but does not address the effects
`of refrigerant emissions on the environment. For information
`on the environmental effects of refrigerant emissions, see
`
`ANSI/ASHRAE Standard 147, Reducing the Release of Halo-
`genated Refrigerants from Refrigerating and Air-Condition-
`ing Equipment and Systems.2
`The hazards of refrigerants are related to their physical
`and chemical characteristics as well as to the pressures and
`temperatures that occur in refrigerating and air-conditioning
`systems. Personal injury and property damage from inadequate
`precautions may occur from a number of origins, such as
`
`(cid:129)
`(cid:129)
`
`(cid:129)
`
`rupture of a part with risk from flying debris;
`release of refrigerant from a fracture, due to a leaking
`seal or incorrect operation; or
`fire resulting from or intensified by burning or deflagra-
`tion of escaping refrigerant or lubricant.
`
`Personal injury resulting from the accidental release of
`refrigerants may also occur from
`
`(cid:129)
`
`(cid:129)
`(cid:129)
`
`(cid:129)
`(cid:129)
`
`suffocation from heavier-than-air refrigerants in inade-
`quately ventilated spaces;
`narcotic and cardiac sensitization effects;
`toxic effects of vapor or the decomposition products due
`to vapor contact with flames or hot surfaces;
`corrosive attack on the eyes, skin, or other tissue; or
`freezing of tissue by contact with liquid.
`
`Care should be taken to avoid stagnant pockets of refrig-
`erant vapors by properly locating ventilation supply air inlets
`and exhaust outlets. All commonly used refrigerants, except
`ammonia (R-717) and water (R-718), are heavier than air.
`Leaked refrigerant vapor will concentrate near the floor if
`undisturbed. Floor-level exhaust-air outlets are appropriate
`for heavier-than-air refrigerants. The user’s manual may pro-
`vide useful guidance for the design of ventilation systems and
`the location of supply air inlets and exhaust outlets.
`The following short publishing history of this code traces
`the origins of these safety provisions. In 1919, the American
`Society of Refrigerating Engineers (ASRE) proposed a Tenta-
`tive Code for the Regulation of Refrigerating Machines and
`Refrigerants. Over the next 11 years, representatives from the
`American Gas Association, American Institute of Electrical
`Engineers, American Institute of Refrigeration, American
`Chemical Society, American Society of Heating and Ventila-
`tion Engineers, American Society of Mechanical Engineers,
`National Electrical Refrigerator Manufacturers Association,
`National Fire Protection Association, and ASRE met to expand
`the code to address all of the issues raised on the use of refrig-
`eration equipment. The first Safety Code for Mechanical
`Refrigeration, recognized as American Standard B9 in Octo-
`ber 1930, appeared in the first edition, 1932–1933, of the
`ASRE Refrigerating Handbook and Catalog. ASRE revisions
`designated ASA B9 appeared in 1933 and 1939. ASRE revi-
`sions designated ASA B9.1 appeared in 1950, 1953, and 1958.
`After the formation of ASHRAE, editions appeared as ASA
`B9.1-1964, ANSI B9.1-1971, ANSI/ASHRAE 15-1978, ANSI/
`ASHRAE 15-1989, ANSI/ASHRAE 15-1992, ANSI/ASHRAE
`15-1994, ANSI/ASHRAE 15-2001, ANSI/ASHRAE 15-2004,
`ANSI/ASHRAE 15-2007, and ANSI/ASHRAE 15-2010.
`
`2
`
`ANSI/ASHRAE Standard 15-2013
`
`© ASHRAE (www.ashrae.org). For personal use only. Additional reproduction, distribution,
`or transmission in either print or digital form is not permitted without ASHRAE's prior written permission.
`
`p
`
`
`
`
`
`
`
`
`
`
`
`6
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
` N
`
` p
`
`
`
`b
`
` p
`
` D
`
`b
`
`
`
`
`
` b
`
`
`
`
`
`
`
`
`
`4 of 82
`
`

`
`1. PURPOSE
`This standard specifies safe design, construction, installa-
`tion, and operation of refrigeration systems.
`
`2. SCOPE
`2.1 This standard establishes safeguards for life, limb, health,
`and property and prescribes safety requirements.
`2.2 This standard applies to
`
`a.
`
`the design, construction, test, installation, operation, and
`inspection of mechanical and absorption refrigeration sys-
`tems,
`including heat-pump systems used in stationary
`applications;
`b. modifications, including replacement of parts or compo-
`nents if they are not identical in function and capacity; and
`substitutions of refrigerant having a different designa-
`tion.
`
`c.
`
`3. DEFINITIONS
`administrative control: the use of human action aimed at
`achieving a safe level of performance from a system or sub-
`system. Compare to engineering control.
`approved: acceptable to the authority having jurisdiction
`(AHJ).
`approved, nationally recognized laboratory: a laboratory that
`is acceptable to the AHJ and provides uniform testing and
`examination procedures and standards for meeting design,
`manufacturing, and factory testing requirements of this code;
`is organized, equipped, and qualified for testing; and has a
`follow-up inspection service of the current production of the
`listed products.
`back pressure: the static pressure existing at the outlet of an
`operating pressure-relief device due to pressure in the dis-
`charge line.
`balanced relief valve: a pressure-relief valve that incorpo-
`rates means of minimizing the effect of back pressure on the
`operational characteristics of the valve (opening pressure,
`closing pressure, and relieving capacity).
`blends: refrigerants consisting of mixtures of two or more
`different chemical compounds, often used individually as
`refrigerants for other applications.
`brazed joint: a gas-tight joint obtained by the joining of metal
`parts with metallic mixtures or alloys that melt at tempera-
`tures above 1000°F (537°C) but less than the melting temper-
`atures of the joined parts.
`cascade refrigerating system: a refrigerating system having
`two or more refrigerant circuits, each with a pressure-impos-
`ing element, a condenser, and an evaporator, where the evapo-
`rator of one circuit absorbs the heat rejected by another (lower-
`temperature) circuit.
`companion or block valves: pairs of mating stop valves that
`allow sections of a system to be joined before opening these
`valves or separated after closing them.
`compound refrigerating system: a multistage refrigerating
`system in which a single charge of refrigerant circulates
`
`through all stages of compression. See multistage refrigerat-
`ing system.
`compressor: a machine used to compress refrigerant vapor.
`compressor unit: a compressor with its prime mover and
`accessories.
`condenser: that part of the refrigerating system where refrig-
`erant is liquefied by the removal of heat.
`condenser coil: a condenser constructed of pipe or tubing, not
`enclosed in a pressure vessel.
`condensing unit: a combination of one or more power-driven
`compressors, condensers, liquid receivers (when required),
`and regularly furnished accessories.
`containers, refrigerant: a cylinder for the transportation of
`refrigerant.
`corridor: an enclosed passageway that limits travel to a single
`path.
`critical pressure, critical temperature, and critical volume:
`a point on the saturation curve where the refrigerant liquid
`and vapor have identical volume, density, and enthalpy and
`there is no latent heat.
`design pressure: the maximum gage pressure for which a
`specific part of a refrigerating system is designed.
`two pressure-relief devices
`dual pressure-relief device:
`mounted on a three-way valve that allows one device to
`remain active while the other is isolated.
`duct: a tube or conduit used to convey or encase.
`air duct: a tube or conduit used to convey air (air pas-
`sages in self-contained systems are not air ducts).
`pipe duct: a tube or conduit used to encase pipe or tubing.
`engineering control: the use of sensors, actuators, and other
`equipment to achieve a safe level of performance from a sys-
`tem or subsystem without the aid of human interaction. Com-
`pare to administrative control.
`evaporator: that part of the refrigerating system designed to
`vaporize liquid refrigerant to produce refrigeration.
`evaporator coil: an evaporator constructed of pipe or tubing,
`not enclosed in a pressure vessel.
`fusible plug: a plug containing an alloy that will melt at a
`specified temperature and relieve pressure.
`header: a pipe or tube (extruded, cast, or fabricated) to which
`other pipes or tubes are connected.
`heat pump: a refrigerating system used to transfer heat into a
`space or substance.
`highside: those portions of the refrigerating system that are
`subject to approximate condensing pressure.
`horsepower: the power delivered from the prime mover to the
`compressor of a refrigerating system.
`immediately dangerous to life or health (IDLH): the maxi-
`mum concentration from which unprotected persons are able
`to escape within 30 minutes without escape-impairing symp-
`toms or irreversible health effects.1
`
`ANSI/ASHRAE Standard 15-2013
`
`3
`
`© ASHRAE (www.ashrae.org). For personal use only. Additional reproduction, distribution,
`or transmission in either print or digital form is not permitted without ASHRAE's prior written permission.
`
`p
`
`
`
`
`
`
`
`
`
`
`
`6
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
` N
`
` p
`
`
`
`b
`
` p
`
` D
`
`b
`
`
`
`
`
` b
`
`
`
`
`
`
`
`
`
`5 of 82
`
`

`
`informative appendix: an appendix that is not part of the
`standard but is included for information only.
`
`inside dimension: inside diameter, width, height, or cross-
`sectional diagonal.
`
`internal gross volume: the volume as determined from inter-
`nal dimensions of the container with no allowance for the vol-
`ume of internal parts.
`
`limited charge system: a system in which, with the compres-
`sor idle, the design pressure will not be exceeded when the
`refrigerant charge has completely evaporated.
`
`liquid receiver: a vessel, permanently connected to a refriger-
`ating system by inlet and outlet pipes, for storage of liquid
`refrigerant.
`
`listed: equipment or materials included in a list published by
`an approved, nationally recognized testing laboratory, inspec-
`tion agency, or other organization concerned with product
`evaluation that maintains periodic inspection of production of
`listed equipment or materials and whose listing states either
`that the equipment or material meets nationally recognized
`standards or has been tested and found suitable for use in a
`specified manner.
`
`lithium bromide/water absorption system: an absorption sys-
`tem where water (R-718) is the refrigerant and lithium bro-
`mide (LiBr) is the absorbent.
`
`lobby: a waiting room or large hallway serving as a waiting
`room.
`
`lower flammability limit (LFL): the minimum concentration
`of the refrigerant that propagates a flame through a homoge-
`neous mixture of refrigerant and air.
`
`lowside: the portion of a refrigerating system that is subjected
`to approximate evaporator pressure.
`
`machinery: the refrigerating equipment forming a part of the
`refrigerating system, including, but not limited to, any or all
`of the following: compressor, condenser,
`liquid receiver,
`evaporator, and connecting piping.
`
`machinery room: a space, meeting the requirements of Sec-
`tions 8.11 and 8.12, that is designed to house compressors and
`pressure vessels.
`
`manufacturer: the company or organization that evidences
`its responsibility by affixing its name, trademark, or trade
`name to refrigerating equipment.
`
`means of egress: a continuous and unobstructed path of travel
`from any point in a building or structure to a public way.
`
`mechanical joint: a gas-tight joint obtained by joining metal
`parts with a positive-holding mechanical construction such as
`flanged, screwed, or flared joints or compression fittings.
`
`multistage refrigerating system: a refrigerating system in
`which compression of refrigerant is carried out in two or more
`steps.
`
`nonpositive displacement compressor: a compressor in which
`the increase in vapor pressure is attained without changing the
`internal volume of the compression chamber.
`
`normative appendix: an appendix including integral parts of
`the mandatory requirements of the standard, which, for rea-
`sons of convenience, are placed after all other normative ele-
`ments.
`occupancy: for class of occupancy, see Section 4.
`occupied space: that portion of the premises accessible to or
`occupied by people, excluding machinery rooms.
`pilot-operated relief valve: a pressure-relief valve in which
`the major relieving device is combined with and is controlled
`by a self-actuated auxiliary pressure-relief valve.
`piping: the pipe or tube used to convey fluid from one part of
`a refrigeration system to another. Piping includes pipe,
`flanges, bolting, gaskets, valves, fittings, pipe-supporting fix-
`tures, structural attachments, and the pressure-containing
`parts of other components, such as expansion joints, strainers,
`filters, and devices that serve such purposes as mixing, sepa-
`rating, muffling, snubbing, distributing, metering, or control-
`ling flow.
`positive displacement compressor: a compressor in which the
`increase in pressure is attained by changing the internal vol-
`ume of the compression chamber.
`premises: a tract of land and the buildings thereon.
`pressure-imposing element: any device or portion of the
`equipment used to increase refrigerant pressure.
`pressure-limiting device: a pressure-responsive electronic or
`mechanical control designed to automatically stop the opera-
`tion of the pressure-imposing element at a predetermined pres-
`sure.
`pressure-relief device: a pressure- (not temperature-) actu-
`ated valve or rupture member designed to automatically
`relieve pressure in excess of its setting.
`pressure-relief valve: a pressure-actuated valve held closed
`by a spring or other means and designed to automatically
`relieve pressure in excess of its setting.
`pressure vessel: any refrigerant-containing receptacle in a
`refrigerating system. This does not include evaporators where
`each separate evaporator section does not exceed 0.5 ft3
`(0.014 m3) of refrigerant-containing volume, regardless of the
`maximum inside dimension. This also does not include evap-
`orator coils, compressors, condenser coils, controls, headers,
`pumps, and piping.
`pumpdown charge: the quantity of refrigerant stored at some
`point in the refrigeration system for operational, service, or
`standby purposes.
`reclaimed refrigerants: refrigerants reprocessed to the same
`specifications as new refrigerants by any means, including
`distillation. Such refrigerants have been chemically analyzed
`to verify that those specifications have been met.
`recovered refrigerants: refrigerants removed from a system
`in any condition without necessarily testing or processing
`them.
`recycled refrigerants: refrigerants for which contaminants
`have been reduced by oil separation, removal of noncondens-
`able gases, and single or multiple passes through filter driers
`
`4
`
`ANSI/ASHRAE Standard 15-2013
`
`© ASHRAE (www.ashrae.org). For personal use only. Additional reproduction, distribution,
`or transmission in either print or digital form is not permitted without ASHRAE's prior written permission.
`
`p
`
`
`
`
`
`
`
`
`
`
`
`6
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
` N
`
` p
`
`
`
`b
`
` p
`
` D
`
`b
`
`
`
`
`
` b
`
`
`
`
`
`
`
`
`
`6 of 82
`
`

`
`or other devices that reduce moisture, acidity, and particulate
`matter.
`
`refrigerant: the fluid used for heat transfer in a refrigerating
`system; the refrigerant absorbs heat and transfers it at a higher
`temperature and a higher pressure, usually with a change of
`state.
`
`refrigerant concentration limit (RCL): the refrigerant con-
`centration limit in air, determined in accordance with ANSI/
`ASHRAE Standard 341and intended to reduce the risks of
`acute toxicity, asphyxiation, and flammability hazards in nor-
`mally occupied, enclosed spaces.
`
`refrigerant detector: a device that is capable of sensing the
`presence of refrigerant vapor.
`
`refrigerating system: a combination of interconnected parts
`forming a closed circuit in which refrigerant is circulated for
`the purpose of extracting, then rejecting, heat. (See Section 5
`for classification of refrigerating systems by type.)
`
`refrigerating system classification: refrigerating systems are
`classified according to the degree of probability, low or high,
`that leaked refrigerant from a failed connection, seal, or com-
`ponent could enter an occupied area. The distinction is based
`on the basic design or location of the components. (See Sec-
`tion 5 for classification of refrigerating systems by type.)
`
`refrigerating system, direct: see Section 5.1.1.
`
`refrigerating system, indirect: see Section 5.1.2.
`
`rupture member: a device that will rupture and release refrig-
`erant to relieve pressure.
`
`saturation pressure: the pressure at which vapor and liquid
`exist in equilibrium at a given temperature.
`
`sealed ammonia/water absorption system: an absorption sys-
`tem where ammonia (R-717) is the refrigerant and water (R-
`718) is the absorbent and all refrigerant-containing parts are
`made permanently tight by welding or brazing.
`
`secondary coolant: any liquid used for the transmission of
`heat, without vaporization.
`
`self-contained system: a complete, factory-assembled and
`factory-tested system that is shipped in one or more sections
`and has no refrigerant-containing parts that are joined in the
`field by other than companion or block valves.
`
`set pressure: the pressure at which a pressure-relief device or
`pressure control is set to operate.
`
`shall (shall not): used in this standard when a provision is (or
`is not) mandatory.
`
`soldered joint: a gas-tight joint formed by joining metal parts
`with alloys that melt at temperatures not exceeding 800°F
`(426.5°C) and above 400°F (204.5°C).
`
`specified: explicitly stated in detail. Specified limits or pre-
`scriptions are mandatory.
`
`stop valve: a device used to shut off the flow of refrigerant.
`
`three-way valve: a service valve for dual pressure-relief
`devices that allows using one device while isolating the other
`from the system, maintaining one valve in operation at all
`times.
`threshold limit value time-weighted average (TLV-TWA†):
`the refrigerant concentration in air for a normal eight-hour
`workday and a 40-hour workweek to which repeated expo-
`sure, day after day, will not cause an adverse effect in most
`persons.
`
`ultimate strength: the stress at which rupture occurs.
`
`unit system: see self-contained system.
`
`unprotected tubing: tubing that is unenclosed and therefore
`exposed to crushing, abrasion, puncture, or similar damage
`after installation.
`
`zeotropic: refers to blends comprising multiple components
`of different volatility that, when used in refrigeration cycles,
`change volumetric composition and saturation temperatures
`as they evaporate (boil) or condense at constant pressure. The
`word is derived from the Greek words zein (to boil) and tro-
`pos (to change).
`
`4. OCCUPANCY CLASSIFICATION
`
`4.1 Locations of refrigerating systems are described by occu-
`pancy classifications that consider the ability of people to
`respond to potential exposure to refrigerant as follows.
`4.1.1 Institutional occupancy is a premise or that portion of
`a premise from which, because they are disabled, debilitated,
`or confined, occupants cannot readily leave without the assis-
`tance of others. Institutional occupancies include, among oth-
`ers, hospitals, nursing homes, asylums, and spaces containing
`locked cells.
`4.1.2 Public assembly occupancy is a premise or that por-
`tion of a premise where large numbers of people congregate
`and from which occupants cannot quickly vacate the space.
`Public assembly occupancies include, among others, auditori-
`ums, ballrooms, classrooms, passenger depots, restaurants,
`and theaters.
`4.1.3 Residential occupancy is a premise or that portion of
`a premise that provides the occupants with complete indepen-
`dent living facilities, including permanent provisions for liv-
`ing, sleeping, eating, cooking, and sanitation. Residential
`occupancies include, among others, dormitories, hotels,
`multi-unit apartments, and private residences.
`4.1.4 Commercial occupancy is a premise or that portion of
`a premise where people transact business, receive personal
`service, or purchase food and other goods. Commercial occu-
`pancies include, among others, office and professional build-
`ings, markets (but not large mercantile occupancies), and
`work or storage areas that do not qualify as industrial occu-
`pancies