EN 378-1:2008+A2:2012

2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.Kälteanlagen und Wärmepumpen - Sicherheitstechnische und umweltrelevante Anforderungen - Teil 1: Grundlegende Anforderungen, Begriffe, Klassifikationen und AuswahlkriterienSystèmes de réfrigération et pompes à chaleur - Exigences de sécurité et d'environnement - Partie 1: Exigences de base, définitions, classification et critères de choixRefrigerating systems and heat pumps - Safety and environmental requirements - Part 1: Basic requirements, definitions, classification and selection criteria27.200Hladilna tehnologijaRefrigerating technology27.080Heat pumps01.040.27Prenos energije in toplote (Slovarji)Energy and heat transfer engineering (Vocabularies)ICS:Ta slovenski standard je istoveten z:EN 378-1:2008+A2:2012SIST EN 378-1:2008+A2:2012en,fr01-julij-2012SIST EN 378-1:2008+A2:2012SLOVENSKI
STANDARD
EUROPEAN STANDARD NORME EUROPÉENNE EUROPÄISCHE NORM
EN 378-1:2008+A2
May 2012 ICS 27.080; 27.200; 01.040.27 Supersedes EN 378-1:2008+A1:2010English Version
Refrigerating systems and heat pumps - Safety and environmental requirements - Part 1: Basic requirements, definitions, classification and selection criteria
Systèmes de réfrigération et pompes à chaleur - Exigences de sécurité et d'environnement - Partie 1: Exigences de base, définitions, classification et critères de choix
Kälteanlagen und Wärmepumpen - Sicherheitstechnische und umweltrelevante Anforderungen - Teil 1: Grundlegende Anforderungen, Begriffe, Klassifikationen und Auswahlkriterien This European Standard was approved by CEN on 13 October 2007 and includes Amendment 1 approved by CEN on 13 November 2010 and Amendment 2 approved by CEN on 23 January 2012.
CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such national standards may be obtained on application to the CEN-CENELEC Management Centre or to any CEN member.
This European Standard exists in three official versions (English, French, German). A version in any other language made by translation under the responsibility of a CEN member into its own language and notified to the CEN-CENELEC Management Centre has the same status as the official versions.
CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION EUROPÄISCHES KOMITEE FÜR NORMUNG
Management Centre:
Avenue Marnix 17,
B-1000 Brussels © 2012 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN 378-1:2008+A2:2012: ESIST EN 378-1:2008+A2:2012

Equivalent terms in English, French and German . 25Annex B (informative)
Total equivalent warming impact (TEWI) . 29Annex C (normative)
Refrigerant charge limitations . 32Annex D (informative)
Protection for people who are inside cold rooms . 46Annex E (normative)
!Safety classification and information about refrigerants"""" . 48Annex F (informative)
Safety group classifications . 56Annex G (normative)
Special requirements for ice rinks . 63Bibliography . 64 SIST EN 378-1:2008+A2:2012

"Refrigerating systems, safety and environmental requirements", the secretariat of which is held by DIN. This European Standard shall be given the status of a national standard, either by publication of an identical text or by endorsement, at the latest by November 2012, and conflicting national standards shall be withdrawn at the latest by November 2012. This document includes Amendment 1, approved by CEN on 2010-11-13 and Amendment 2, approved by CEN on 2012-01-23. This document supersedes #EN 378-1:2008+A1:2010$. The start and finish of text introduced or altered by amendment is indicated in the text by tags ! "
and # $. Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. CEN [and/or CENELEC] shall not be held responsible for identifying any or all such patent rights. EN 378 consists of the following parts under the general title Refrigerating systems and heat pumps — Safety and environmental requirements:  Part 1: Basic requirements, definitions, classification and selection criteria  Part 2: Design, construction, testing, marking and documentation  Part 3: Installation site and personal protection  Part 4: Operation, maintenance, repair and recovery According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and United Kingdom.
construction, installation, operation, maintenance, repair and disposal of refrigerating systems and appliances in respect to the local and global environments, but not to the final destruction of the refrigerants. The term "refrigerating system" used in this European Standard includes heat pumps. The extent to which hazards are covered is indicated below. In addition, machinery should comply as
appropriate with EN ISO 12100-1 and EN ISO 12100-2 for hazards which are not covered by this European Standard. It is intended to minimize possible hazards to persons, property and the environment from refrigerating
systems and refrigerants. These hazards are associated essentially with the physical and chemical
characteristics of refrigerants as well as the pressures and temperatures occurring in refrigeration cycles. Inadequate precautions may result in:  component rupture or explosion, with risk of projectiles;  escape of refrigerant with the risk of environmental damage or toxicity due to a fracture, a leakage caused by bad design, incorrect operation, and inadequate maintenance, repair, charging or disposal;  burning or combustion of escaping refrigerant with consequent risk of fire including the risk of toxic
products of combustion from non-flammable refrigerants. Refrigerants, their mixtures and combinations with oils, water or other materials, which are present in the
refrigerating system, intended or unintended, affect the internal surrounding materials chemically and
physically for example due to pressure and temperature. They can, if they have detrimental properties,
endanger persons, property and the environment directly or indirectly due to global long term effects (ODP,GWP) when escaping from the refrigerating system. Refrigerants shall be selected with due regard to their potential influence on the global environment as well as their possible effects on the local environment. Evaluation of the environmental performance however requires a life cycle approach. With regard to global climate change the Total Equivalent Warming Impact approach is generally used as the basis (see Annex B). Reference should be made to the EN ISO 14040 series to address other environmental aspects. Many factors influence environmental impacts such as:  location of the system;  energy efficiency of the system;  type of refrigerant;  service frequency;  refrigerant leaks;  sensitivity of charge on efficiency;  minimisation of heat load;  control methods. The cost of the system will have an indirect influence on the environmental performance. Additional
investments may be directed towards reducing leaks, increasing energy efficiency or modifying the design in order to use a different refrigerant. Only a life cycle approach is capable of identifying where additional
investments will have the most beneficial effects. SIST EN 378-1:2008+A2:2012

simultaneous presence of the liquid and vapour phases. Furthermore, the state of the refrigerant and the stresses that it exerts on the various components do not depend solely on the processes and functions inside the plant, but also on external factors. The following hazards are worthy of note: a) from the direct effect of extreme temperature, for example:  brittleness of materials at low temperatures;  freezing of enclosed liquid (water, brine or similar);  thermal stresses;  changes of volume due to temperature changes;  injurious effects to persons caused by low temperatures;  touchable hot surfaces. b) from excessive pressure due to, for example:  increase in the pressure of condensation, caused by inadequate cooling or the partial pressure of non condensable gases or an accumulation of oil or liquid refrigerant;  increase in the pressure of saturated vapour due to excessive external heating, for example of a
liquid cooler, or when defrosting an air cooler or high ambient temperature when the plant is at a standstill;  expansion of liquid refrigerant in a closed space without the presence of vapour, caused by a rise in external temperature;  fire. c) from the direct effect of the liquid phase, for example:  excessive charge or flooding of equipment;  presence of liquid in compressors, caused by syphoning, or condensation in the compressor;  liquid hammer in piping;  loss of lubrication due to dilution of oil;  condensation-induced shock. d) from the escape of refrigerants, for example:  fire;  explosion;  toxicity including products of combustion;  caustic effects;  freezing of skin; SIST EN 378-1:2008+A2:2012

discharge, liquid slugging, erroneous operation and reduction in mechanical strength caused by corrosion, erosion, thermal stress, liquid hammer or vibration. Corrosion, however, should have special consideration as conditions peculiar to refrigerating systems arise due to alternate frosting and defrosting or the covering of equipment by insulation. The above analysis of the hazards applying to refrigerating systems explains the plan on which this European Standard has been based. SIST EN 378-1:2008+A2:2012

limitations of part 1 (Annex C) apply. For refrigerating systems with a limited mass of refrigerant only some of the parts and clauses are
applicable. The exceptions are defined in the scope and the clauses of each part of EN 378. This European Standard is not applicable to refrigerating systems with air or water as refrigerant.
Systems using refrigerants other than those listed in Annex E are not covered by this European Standard as long as a safety class is not assigned. NOTE 2 For the safety classification of refrigerant fluids not included in Annex E, see Annex F. This European Standard covers the hazards mentioned in the introduction. This European Standard is applicable to new refrigerating systems and modification of existing refrigerating systems in case the type of refrigerant changed or pressure vessels are replaced. The part dealing with main-tenance, repair, operation, recovery, reuse and disposal also applies to existing systems. Parties
responsible for existing refrigerating systems should consider the safety and environmental aspects of this European Standard and implement the more stringent requirements so far as they are reasonably practicable. Directive 94/9/EC concerning equipment and protective systems intended for use in potentially explosive
atmospheres can be applicable to the type of machine or equipment covered by this European Standard. The present standard is not intended to provide means of complying with the essential health and safety
requirements of Directive 94/9/EC. 2 Normative references The following referenced documents are indispensable for the application of this document. For dated refer-ences, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. EN 378-2, Refrigerating systems and heat pumps — Safety and environmental requirements — Part 2: De-sign, construction, testing, marking and documentation 3 Terms and definitions For the purposes of this document, the following terms and definitions apply. NOTE See informative Annex A for equivalent terms in English, French and German. SIST EN 378-1:2008+A2:2012

transported in one or more sections and in which no refrigerant containing parts are connected on site other than by companion or block valves 3.1.3 unit system self-contained system that has been assembled, filled ready for use and tested prior to its installation and is installed without need for connecting any refrigerant containing parts NOTE A unit system can include factory assembled companion or block valves. 3.1.4 limit charged system refrigerating system in which the internal volume and total refrigerant charge are such that, with the system idle, the allowable pressure will not be exceeded if complete evaporation of the refrigerant charge occurs 3.1.5 absorption or adsorption system refrigerating system in which refrigeration is achieved by evaporation of a refrigerant, the vapour then being absorbed or adsorbed by an absorbent or adsorbent medium respectively, from which it is subsequently
expelled at a higher partial vapour pressure by heating and then liquefied by cooling 3.1.6 secondary cooling or heating system system employing a fluid which transfers heat from the product or spaces to be cooled or heated or from
another cooling or heating system to the refrigerating system without compression and expansion of the fluid #deleted text$ #3.1.7$ sealed system refrigerating system in which all refrigerant containing parts are made tight by welding, brazing or a similar permanent connection #NOTE 1$
A connection that is tightness tested for a leakage rate of less than 3 g refrigerant per year under a pressure of at least 0,25 × PS and where the mechanical joints are prevented from improper use by the need of a special tool, glue etc.) is considered as a similar permanent connection. This may include valves with seal cap and capped service ports. #NOTE 2
Hermetically sealed systems in EN 16084 are equivalent to sealed systems in EN 378.$ #3.1.8$ high pressure side part of a refrigerating system operating at approximately the condenser or gascooler pressure #3.1.9$ low pressure side part of a refrigerating system operating at approximately the evaporator pressure SIST EN 378-1:2008+A2:2012

refrigerating systems, e.g. transport of refrigerated cargo by road, train and containers. #3.1.11$ cascade system two or more independent refrigeration circuits where the condenser of one systems rejects heat directly to the evaporator of another #3.1.12$ transcritical cycle refrigerating cycle whose compressor discharges refrigerant at a condition (pressure) above the critical point #3.1.13$ assembly discrete unit with defined function (e.g. a condensing unit) made up from several components. Assemblies are often connected together on-site to make a complete system #3.1.14$ component individual functional item or sub-assembly of a refrigerating system NOTE Does not include parts of sub-assemblies e.g. seals, fasteners. 3.2 Occupancies, localities 3.2.1 machinery room (location) complete enclosed room or space #deleted text$ only accessible to authorised
persons, which is intended for the installation of components of the refrigerating system or of the complete refrigerating system. Other equipment may also be installed provided it is compatible with the safety
requirements for the refrigerating system 3.2.2 special machinery room (location) machinery room intended only for the installation of the complete refrigerating system or components of the refrigerating system. It is accessible only to competent personnel for the purposes of maintenance and repair 3.2.3 occupied space (occupancy) complete enclosed space which is occupied for a significant period by people. Where the spaces around the apparent occupied space are, by construction or design, not adequately tight, these are also considered as part of the occupied space. These can be for example voids above false ceilings, crawl ways, ducts and
movable partitions. The occupied space may be accessible to the public (for example supermarket) or only to trained persons (for example cutting up of meat). In an occupied space, both parts of a refrigerating system or the complete refrigerating system may be located/installed 3.2.4 air lock isolating chamber provided with separate entrance and exit doors allowing passage from one place to another whilst isolating one from the other 3.2.5 lobby entrance hall or large hallway serving as a waiting room SIST EN 378-1:2008+A2:2012

walking 3.3 Pressures 3.3.1 gauge pressure pressure for which the value is equal to the difference between the absolute pressure and atmospheric
pressure NOTE All pressures are gauge pressures, unless otherwise indicated. 3.3.2 maximum allowable pressure maximum pressure for which the equipment is designed, as specified by the manufacturer NOTE 1 Limit to the operating pressure which should not be exceeded either when the system is working or not. NOTE 2 The Pressure Equipment Directive 97/23/EC identifies the maximum allowable pressure by the symbol "PS". NOTE 3 The subscript “max” is added to the symbol for maximum values. 3.3.3 design pressure pressure chosen for the derivation of the calculation pressure of each component NOTE It is used for determining the necessary materials, thickness and construction for components with regard to their ability to withstand pressure. SIST EN 378-1:2008+A2:2012

adsorber, liquid receiver, evaporator, surge drum 3.4.3 compressor device for mechanically increasing the pressure of a refrigerant vapour 3.4.4 motorcompressor fixed combination of electrical motor and compressor in one unit 3.4.4.1 hermetic motorcompressor combination of a compressor and electrical motor, both of which are enclosed in the same housing, with no external shaft or shaft seals, the electrical motor operating in a mixture of oil and refrigerant vapour 3.4.4.2 semihermetic (accessible hermetic) motorcompressor combination consisting of a compressor and electrical motor, both of which are enclosed in the same housing, having removable covers for access, but having no external shaft or shaft seals, the electrical motor operating in a mixture of oil and refrigerant vapour 3.4.4.3 canned rotor motorcompressor motorcompressor within a sealed housing not enclosing the motor windings and having no external shaft 3.4.5 open compressor compressor having a drive shaft penetrating the refrigerant-tight housing 3.4.6 positive displacement compressor compressor in which compression is obtained by changing the internal volume of the compression chamber 3.4.7 non-positive displacement compressor compressor in which compression is obtained without changing the internal volume of the compression
chamber SIST EN 378-1:2008+A2:2012

serving as a heat exchanger (evaporator or condenser) 3.4.15 compressor unit combination of one or more compressors and the regularly furnished accessories 3.4.16 condensing unit combination of one or more compressors, condensers, liquid receivers (when required) and the regularly
furnished accessories SIST EN 378-1:2008+A2:2012

return pipes to an evaporator(s) 3.4.18 internal gross volume volume calculated from the internal dimensions of a vessel, no account being taken of the volume of any
internal parts 3.4.19 internal net volume volume calculated from the internal dimensions of a vessel, and excluding the volume of the permanent
internal parts 3.4.20 type approved component component for which examination is performed on one or more samples of this component in accordance with a recognised standard for type approval 3.5 Piping and joints 3.5.1 piping all piping covered in the scope of EN 14276-2 such as pipes or tubes (including hoses, bellows, fittings, or flexible pipes) for interconnecting the various parts of a refrigerating system 3.5.2 joint connection made between two parts 3.5.3 welded joint joint obtained by the joining of metal parts in the plastic or molten state 3.5.4 brazed joint joint obtained by the joining of metal parts with alloys which melt at temperatures in general higher than 450 °C but less than the melting temperatures of the joined parts 3.5.5 soldered joint joint obtained by the joining of metal parts with metallic mixtures or alloys which melt at temperatures in
general less than 450 °C 3.5.6 soft soldered joint joint obtained by joining of metal parts with metallic mixtures or alloys which melt below 200 °C 3.5.7 flanged joint joint made by bolting together a pair of flanged ends 3.5.8 flared joint metal-to-metal compression joint in which a conical spread is made on the end of the tube SIST EN 378-1:2008+A2:2012

automatically resets NOTE It is called PSH for high pressure protection and PSL for low pressure protection. 3.6.7.3 type approved pressure cut out safety switching device for limiting the pressure that is type approved according to EN 12263 which manually resets without the aid of a tool NOTE It is called PZH for high pressure protection and PZL for low pressure protection. 3.6.7.4 type approved safety pressure cut out safety switching device for limiting the pressure that is type approved according to EN 12263 which manually resets only with the aid of a tool NOTE It is called PZHH for high pressure protection and PZLL for low pressure protection. 3.6.8 changeover device valve controlling two safety devices and so arranged that only one can be made inoperative at any one time 3.6.9 refrigerant detector sensing device which responds to a pre-set concentration of refrigerant gas in the environment 3.6.10 overflow valve pressure relief device discharging to a part of the refrigerating system with lower pressure 3.6.11 surge protection device device which shuts down the compressor after a few surge pulses (e.g. by measuring pressure differences across the compressor or current input to the drive motor) SIST EN 378-1:2008+A2:2012

pressure and rejects heat at a higher temperature and a higher pressure usually involving changes of the state of the fluid 3.7.2 heat-transfer medium fluid for the transmission of heat usually without any change in its phase (e.g. brine, water, air) or with a change in its phase at the same pressure (e.g. R744). When fluids listed in Annex E are used they need to comply with all requirements of refrigerants — even if they are used as a heat transfer medium 3.7.3 toxicity ability of a fluid to be harmful or lethal due to acute or chronic exposure by contact, inhalation or ingestion NOTE Temporary discomfort that does not impair health is not considered to be harmful. 3.7.4 lower flammability limit (LFL) minimum concentration of refrigerant that is capable of propagating a flame within a homogeneous mixture of refrigerant and air 3.7.5 fractionation change in composition of a refrigerant mixture by e.g. evaporation of the more volatile component(s) or
condensation of the less volatile component(s) 3.7.6 outside air air from outside the building 3.7.7 halocarbon and hydrocarbon these are:  CFC: fully-halogenated halocarbon containing only chlorine, fluorine and carbon;  HCFC: halocarbon containing hydrogen, chlorine, fluorine and carbon;  HFC: halocarbon containing only hydrogen, fluorine and carbon;  PFC: fully fluorinated halocarbon containing only fluorine and carbon;  HC: hydrocarbon containing only hydrogen and carbon SIST EN 378-1:2008+A2:2012

refrigerant first begins to boil NOTE The bubble point of a zeotropic refrigerant blend, at constant pressure, is lower than the dew point. 3.7.13 autoignition temperature of a substance lowest temperature at or above which a chemical can spontaneously combust in a normal atmosphere without an external source of ignition, such as a flame or spark 3.8 Miscellaneous 3.8.1 competence ability to perform satisfactorily the activities within an occupation NOTE Levels of competence are defined in EN 13313. 3.8.2 comfort air conditioning method of air treatment designed to satisfy the comfort requirements of the occupants 3.8.3 self-contained breathing apparatus breathing apparatus which has a portable supply of compressed air, independent of the ambient atmosphere, where exhaust air passes without recirculation to the ambient atmosphere 3.8.4 vacuum procedure procedure to check the gas tightness of an uncharged system by drawing a vacuum NOTE Evacuation also removes moisture from a system. SIST EN 378-1:2008+A2:2012

abnormal operation of the refrigerating system. Considerations of safety in refrigerating systems take into
account the site, the number of people occupying the site and the categories of occupancy. Machinery rooms (see 3.2.1 and 3.2.2) are regarded as unoccupied. 4.2.2 General occupancy — Class A A location where people may sleep or where the number of people present is not controlled or to which any person has access without being personally acquainted with the personal safety precautions. EXAMPLES hospitals, prisons, nursing homes, theatres, supermarkets, transport termini, hotels, lecture halls,
dwellings, restaurants, ice rinks 4.2.3 Supervised occupancy — Class B Rooms, parts of buildings or buildings, where only a limited number of people may be assembled, some of them being necessarily acquainted with the general safety precautions. EXAMPLES laboratories, places for general manufacturing, office buildings SIST EN 378-1:2008+A2:2012

Authorised persons shall be acquainted with general safety precautions of the establishment (e.g. industrial production facilities). EXAMPLES cold stores, refineries, abattoirs, non-public areas in supermarkets, manufacturing facilities e.g. for chemicals, food, ice and ice cream 4.2.5 More than one category of occupancy Where there is the possibility of more than one category of occupancy, the more stringent requirements apply. If occupancies are isolated, e.g. by sealed partitions, floors and ceilings, then the requirements of the
individual category of occupancy apply. NOTE Attention is drawn to the safety of adjacent premises and occupants in areas adjacent to a refrigerating
system. Refrigerants heavier than air can cause oxygen deficient pockets at low level (see molar mass in the informative
Annex F). Table 1 — Category of occupancy Categories General characteristics Examples a General
occupancy A Rooms, parts of buildings, building where — people may sleep; — people are restricted in their move-ment; — an uncontrolled number of people are present or to which any person has access without being personally acquainted with the necessary safety precautions. Hospitals, courts or prisons, theatres, supermarkets, schools, lecture halls, public transport termini, hotels, dwellings, restaurants. Supervised
occupancy B Rooms, parts of buildings, buildings where only a limited number of people may be assembled, some being necessarily ac-quainted with the general safety precau-tions of the establishment. Business or professional offices, laboratories, places for general manufacturing and where people work. Authorised
occupancy C Rooms, parts of buildings, buildings where only authorized persons have access, who are acquainted with general and special safety precautions of the establishment and where manufacturing, processing or storage of material or products take place. Manufacturing facilities, e.g. for chemicals, food, beverage, ice, ice-cream, refineries, cold stores, dairies, abattoirs, non-public areas in supermarkets. a
The list of examples is not exhaustive. 4.3 Designation and Classification of refrigerants Refrigerants are classified according to their flammability and toxicity as defined in Annex F. The designations and classifications of refrigerants are listed in Annex E which includes the fluid groups as defined in Directive 97/23/EC (Pressure Equipment Directive). SIST EN 378-1:2008+A2:2012

Key 1 occupied space 2 refrigerant containing part(s) Figure 1 a — Direct system 4.4.1.2 Open spray system Heat transfer medium in direct contact with refrigerant containing parts, where the indirect circuit is open to the occupied space. A refrigerant leak could enter the occupied space.
Key 1 occupied space 2 refrigerant containing part(s) Figure 1 b — Open spray system 4.4.1.3 Direct ducted system Ducted air in direct contact with refrigerant containing parts, where the conditioned air is supplied to the
occupied space. A refrigerant leak could enter the occupied space. SIST EN 378-1:2008+A2:2012

Key 1 occupied space 2 refrigerant containing part(s) Figure 1 c — Direct ducted system 4.4.1.4 Open vented spray system Heat transfer medium in direct contact with refrigerant containing parts, where the indirect circuit is open to the occupied space. A refrigerant leak could enter the occupied space.
Key 1 occupied space 2 refrigerant containing part(s) Figure 1 d — Open vented spray system 4.4.2 Indirect systems 4.4.2.1 Indirect closed system Where a heat transfer medium is in direct communication with refrigerant containing parts, passing into the occupied space. A refrigerant leak into the indirect circuit could leak into the occupied space. SIST EN 378-1:2008+A2:2012

Key 1 occupied space 2 refrigerant containing part(s) Figure 2 a — Indirect closed system 4.4.2.2 Indirect vented system Where a heat transfer medium is in direct communication with refrigerant containing parts within a vented, or double-walled heat exchanger. A refrigerant leak will be vented out of the heat exchanger and not into the
indirect circuit.
Key 1 occupied space 2 refrigerant containing part(s) Figure 2 b — Indirect vented system 4.4.2.3 Indirect vented closed system Where a heat transfer medium is in direct communication with refrigerant containing parts and the indirect
circuit contains a refrigerant vent within the circuit. A refrigerant leak will be vented from the circuit. SIST EN 378-1:2008+A2:2012

Key 1 occupied space 2 refrigerant containing part(s) Figure 2 c — Indirect vented closed system 4.4.2.4 Double indirect system Where a heat transfer medium is in direct communication with refrigerant containing parts and heat is
exchanged with a second indirect circuit that passes into th
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