prEN ISO 19659-1

Railway applications - Heating, ventilation and air conditioning systems for rolling stock - Part 1: Terms and definitions (ISO 19659-1:2017)

This document is applicable to rail vehicles and specifies the terms, definitions, symbols and abbreviated terms to be used in the ISO 19659 series, heating, ventilation and air conditioning for rolling stock.

Bahnanwendungen - Heizung, Lüftung und Klimatisierung von Schienenfahrzeugen - Teil 1: Begriffe und Definitionen (ISO 19659-1:2017)

Applications ferroviaires - Systèmes de chauffage, ventilation et climatisation pour le matériel roulant - Partie 1: Termes et définitions (ISO 19659-1:2017)

Železniške naprave - Ogrevalni, prezračevalni in klimatski sistemi za vozna sredstva - 1. del: Izrazi in definicije (ISO 19659-1:2017)

General Information

• Status: Not Published
• Publication Date: 02-Sep-2025
• ICS: 01.040.45 - Railway engineering (Vocabularies)
• ICS: 45.060.01 - Railway rolling stock in general
• Technical Committee: CEN/TC 256 - Railway applications
• Drafting Committee: CEN/TC 256/WG 8 - Air conditionning, Heating and Ventilation
• Current Stage: 4060 - Closure of enquiry - Enquiry
• Start Date: 20-Jul-2023
• Due Date: 27-Feb-2024
• Completion Date: 20-Jul-2023
• Ref Project: oSIST prEN ISO 19659-1:2023 - Railway applications - Heating, ventilation and air conditioning systems for rolling stock - Part 1: Terms and definitions (ISO 19659-1:2017)

Standards Content (Sample)

SLOVENSKI STANDARD
oSIST prEN ISO 19659-1:2023
01-julij-2023
Železniške naprave - Ogrevalni, prezračevalni in klimatski sistemi za vozna
sredstva - 1. del: Izrazi in definicije (ISO 19659-1:2017)

Railway applications - Heating, ventilation and air conditioning systems for rolling stock -

Part 1: Terms and definitions (ISO 19659-1:2017)
Bahnanwendungen - Heizung, Lüftung und Klimatisierung von Schienenfahrzeugen -
Teil 1: Begriffe und Definitionen (ISO 19659-1:2017)

Applications ferroviaires - Systèmes de chauffage, ventilation et climatisation pour le

matériel roulant - Partie 1: Termes et définitions (ISO 19659-1:2017)
Ta slovenski standard je istoveten z: prEN ISO 19659-1
ICS:
01.040.45 Železniška tehnika (Slovarji) Railway engineering
(Vocabularies)
45.060.01 Železniška vozila na splošno Railway rolling stock in
general
oSIST prEN ISO 19659-1:2023 en,fr,de

2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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oSIST prEN ISO 19659-1:2023
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oSIST prEN ISO 19659-1:2023
INTERNATIONAL ISO
STANDARD 19659-1
First edition
2017-08
Railway applications — Heating,
ventilation and air conditioning
systems for rolling stock —
Part 1:
Terms and definitions
Applications ferroviaires — Systèmes de chauffage, ventilation et
climatisation pour le matériel roulant —
Partie 1: Termes et définitions
Reference number
ISO 19659-1:2017(E)
ISO 2017
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oSIST prEN ISO 19659-1:2023
ISO 19659-1:2017(E)
COPYRIGHT PROTECTED DOCUMENT
© ISO 2017, Published in Switzerland

All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized otherwise in any form

or by any means, electronic or mechanical, including photocopying, or posting on the internet or an intranet, without prior

written permission. Permission can be requested from either ISO at the address below or ISO’s member body in the country of

the requester.
ISO copyright office
Ch. de Blandonnet 8 • CP 401
CH-1214 Vernier, Geneva, Switzerland
Tel. [phone]
Fax [phone]
[e-mail]
www.iso.org
ii © ISO 2017 – All rights reserved
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ISO 19659-1:2017(E)
Contents Page

Foreword ........................................................................................................................................................................................................................................iv

Introduction ..................................................................................................................................................................................................................................v

1 Scope ................................................................................................................................................................................................................................. 1

2 Normative references ...................................................................................................................................................................................... 1

3 Terms and definitions ..................................................................................................................................................................................... 1

4 Symbols and abbreviated terms ........................................................................................................................................................18

4.1 Symbols ......................................................................................................................................................................................................18

4.2 Abbreviated terms ............................................................................................................................................................................19

Bibliography .............................................................................................................................................................................................................................20

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Foreword

ISO (the International Organization for Standardization) is a worldwide federation of national standards

bodies (ISO member bodies). The work of preparing International Standards is normally carried out

through ISO technical committees. Each member body interested in a subject for which a technical

committee has been established has the right to be represented on that committee. International

organizations, governmental and non-governmental, in liaison with ISO, also take part in the work.

ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of

electrotechnical standardization.

The procedures used to develop this document and those intended for its further maintenance are

described in the ISO/IEC Directives, Part 1. In particular the different approval criteria needed for the

different types of ISO documents should be noted. This document was drafted in accordance with the

editorial rules of the ISO/IEC Directives, Part 2 (see www.iso.org/directives).

Attention is drawn to the possibility that some of the elements of this document may be the subject of

patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of

any patent rights identified during the development of the document will be in the Introduction and/or

on the ISO list of patent declarations received (see www.iso.org/patents).

Any trade name used in this document is information given for the convenience of users and does not

constitute an endorsement.

For an explanation on the voluntary nature of standards, the meaning of ISO specific terms and

expressions related to conformity assessment, as well as information about ISO's adherence to the

World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT) see the following

URL: www.iso.org/iso/foreword.html.

This document was prepared by Technical Committee ISO/TC 269, Railway applications, Subcommittee

SC 2, Rolling stock.
A list of all parts in the ISO 19659 series can be found on the ISO website.
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Introduction

The ISO 19659 series defines terms, thermal comfort, energy efficiency and system installation of

heating, ventilation and air conditioning (HVAC) for rolling stock.

The purpose of this document is to standardize the terms, definitions, symbols and abbreviated terms

used throughout trains systems for the cooling, heating and internal air circulation that are commonly

known as heating, ventilation and air conditioning (HVAC). These can be broken down into multiples of

these functions and as an example, ventilation and air conditioning (VAC), etc.
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oSIST prEN ISO 19659-1:2023
INTERNATIONAL STANDARD ISO 19659-1:2017(E)
Railway applications — Heating, ventilation and air
conditioning systems for rolling stock —
Part 1:
Terms and definitions
1 Scope

This document is applicable to rail vehicles and specifies the terms, definitions, symbols and abbreviated

terms to be used in the ISO 19659 series, heating, ventilation and air conditioning for rolling stock.

2 Normative references
There are no normative references in this document.
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.

ISO and IEC maintain terminological databases for use in standardization at the following addresses:

— IEC Electropedia: available at http://www.electropedia.org/
— ISO Online browsing platform: available at http://www.iso.org/obp
3.1 HVAC system
3.1.1 Function
3.1.1.1
cooling
process which enables the interior temperature to be lowered or maintained
3.1.1.2
pre-cooling

process which enables the interior temperature to be lowered (without the presence of passengers)

3.1.1.3
dehumidification
process which removes water vapour from air to reduce the absolute humidity

[SOURCE: ISO/TR 16344:2012, 2.1.32, modified — “relative humidity” has been changed to “absolute

humidity”.]
3.1.1.4
heating
process which enables the interior temperature to be raised or maintained
3.1.1.5
pre-heating

process which enables the interior temperature to be raised (without the presence of passengers)

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3.1.1.6
supplementary heating
additional heating (3.1.1.4) which provides support for the HVAC system
Note 1 to entry: This can also be referred to as “auxiliary heating”.
3.1.1.7
ventilation
movement of fresh (outside) air to and/or recirculating air in an enclosed space
3.1.1.8
natural air ventilation
air circulation generated without a mechanical action
3.1.1.9
forced air ventilation
air circulation generated by a mechanical action
3.1.1.10
emergency ventilation
ventilation (3.1.1.7) if main power source has failed
3.1.1.11
filtering
process which removes particles from the air
3.1.1.12
purifying
process which removes non-particulate contaminants from the air

Note 1 to entry: Odours and pathogens are examples of non-particulate contaminants from the air.

3.1.1.13
heat recovery

process which transfers heat (latent/sensible) between fresh air (3.4.1) and exhaust air (3.4.10)

3.1.2 Position
3.1.2.1
centralized system
system which consists of one set of HVAC unit (3.1.3.1) per car
3.1.2.2
decentralized system
system which consists of two or more sets of HVAC unit (3.1.3.1) per car
Note 1 to entry: This can also be referred to as “dispersed system”.
3.1.3 Equipment
3.1.3.1
HVAC unit

unit intended for cooling (3.1.1.1) and/or dehumidification (3.1.1.3) and/or heating (3.1.1.4), and/or

ventilation (3.1.1.7)
3.1.3.2
controller unit

unit which operates the HVAC system in a predetermined behaviour while exchanging data with

external devices
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3.1.3.3
cooling unit
system which provides cooling (3.1.1.1)
Note 1 to entry: See Figure 2 to Figure 5.
3.1.3.4
heating unit
system which provides heating (3.1.1.4)
Note 1 to entry: See Figure 2 to Figure 5.
3.1.3.5
supplementary heater

heater that carries out a heating (3.1.1.4) function in a decentralized manner either associated with

forced air ventilation (3.1.1.9) or not
Note 1 to entry: This can also be referred to as “auxiliary heater”.

Note 2 to entry: This can include floor heater, roof heater, body side heater, entrance heater, duct heater, etc.

Note 3 to entry: See Figure 5.
3.1.3.6
total heat exchanger
device using temperature and humidity difference to recover energy
3.1.3.7
ventilation unit
system ensuring ventilation (3.1.1.7)
Note 1 to entry: See Figure 3.
3.1.3.8
exhaust air fan
exhaust air unit

device or unit providing the extraction of air by mechanical action to the outside

Note 1 to entry: See Figure 4.
3.1.3.9
supplementary fan
device installed outside of HVAC unit (3.1.3.1) to move the air locally
Note 1 to entry: See Figure 3.
3.1.3.10
booster fan

supplementary fan (3.1.3.9) used to compensate (part of) the pressure drop inside air ducts

3.1.3.11
pressure protection device

device providing protection against undue vehicle interior tympanic pressure variations caused by

exterior pressure variations
3.1.3.12
pressure protection fan

device providing pressure protection while maintaining a certain degree of ventilation (3.1.1.7)

3.1.3.13
ducting
installations that guide air flows
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3.1.3.14
air diffuser

device for blowing the air in one or more directions while reducing the air velocity

3.1.3.15
air grille
device that provides physical protection, yet allows air to pass through
3.1.3.16
silencer
device to reduce air borne noise
3.1.4 Operation
3.1.4.1
automatic mode
automatic operating mode

operating mode of control in which the HVAC system operates in accordance with the programme data

until stopped by the programme or the operator
[SOURCE: ISO 13041-1:2004, 3.3.4, modified and adapted to HVAC system]
3.1.4.2
cooling mode
operating mode in which the HVAC unit (3.1.3.1) provides cooling (3.1.1.1)
3.1.4.3
forced cooling mode
mode which manually operates HVAC unit (3.1.3.1) cooling mode (3.1.4.2)
3.1.4.4
pre-cooling mode

mode which enables the interior temperature to be lowered (without the presence of passengers)

3.1.4.5
free cooling mode

operating mode in which the HVAC system provides cooling (3.1.1.1) by only introducing fresh air (3.4.1)

3.1.4.6
heating mode
operating mode in which the HVAC system provides heating (3.1.1.4)
3.1.4.7
heat pump mode

mode which can heat the interior by altering the heat emission and removal from the heat exchangers

(3.2.3.5) by changing the refrigerant (3.2.3.3) flow
3.1.4.8
forced heating mode
mode which manually operates HVAC unit (3.1.3.1) heating mode (3.1.4.6)
3.1.4.9
pre-heating mode

mode which enables the interior temperature to be raised (without the presence of passengers)

3.1.4.10
ventilation mode
mode which provides ventilation (3.1.1.7) only
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3.1.4.11
frost protection mode
mode to raise temperatures and avoid interior freezing
3.1.4.12
degraded mode
operation of the HVAC system with defined limitations in performance
3.1.4.13
power save mode

mode which actively reduces its power consumption by allowing parameters to change

Note 1 to entry: Set point and fresh air (3.4.1) are examples of parameters.
3.1.4.14
standby mode

mode under which a predetermined interior temperature range is maintained during non-operational

activity of the vehicle
3.1.4.15
emergency mode

mode which provides reduced ventilation (3.1.1.7), heating (3.1.1.4) and/or cooling (3.1.1.1) if the main

power source has failed
3.1.4.16
maintenance mode

mode used for the purpose of maintenance activities which calls up automatic predefined testing

3.1.4.17
test mode

mode used for the purpose of test activities which calls up a specified routine or requires some specific

testing during maintenance
3.1.4.18
washing mode
mode for external cleaning of train
3.1.5 Performance
3.1.5.1
cooling capacity

enthalpy reduction between the fresh air (3.4.1) and/or return air (3.4.11) on one hand and primary air

(3.4.4) on the other hand in a defined interval of time
3.1.5.2
pre-cooling time

time needed for lowering the interior temperature to pre-cooling (3.1.1.2) set point

3.1.5.3
heating capacity

enthalpy elevation between the fresh air (3.4.1) and/or return air (3.4.11) on one hand and primary air

(3.4.4) on the other hand which can be supported by the supplementary heater (3.1.3.5) in a defined

interval of time
3.1.5.4
pre-heating time

time needed for increasing the interior temperature to pre-heating (3.1.1.5) set point

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3.1.5.5
design conditions

specified exterior/interior boundary conditions under which the thermal comfort (3.7.1) parameters

need to be achieved
3.1.5.6
rated conditions
set of operating conditions specified in a contractual/technical specification
3.1.5.7
standard rating conditions

mandatory condition that is used for marking and for comparison or certification purposes

[SOURCE: ISO 13612-2:2014, 3.40]
3.1.5.8
extreme conditions

specified exterior/interior boundary conditions beyond the design conditions (3.1.5.5) under which the

functionality of the HVAC system installation is maintained but thermal comfort (3.7.1) parameters do

not need to be achieved
3.1.5.9
volume flow
volumetric air flow rate which passes per unit time
3.1.5.10
water tightness
ability of the closed test specimen to resist water penetration
[SOURCE: ISO 15821:2007, 3.6]
3.2 HVAC unit
3.2.1 Type
3.2.1.1
compact HVAC unit

unit where all refrigerant (3.2.3.3) components are installed in the same location

Note 1 to entry: This can also be referred to as “packaged” or “self-contained”.
3.2.1.2
split HVAC unit
unit where refrigerant (3.2.3.3) components are installed in different locations
3.2.2 Location
3.2.2.1
roof mounted
mounted on the roof
Note 1 to entry: See Figure 1 a).
3.2.2.2
roof embedded
installed in the roof
Note 1 to entry: See Figure 1 b).
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3.2.2.3
ceiling mounted
installed between the ceiling and the roof
Note 1 to entry: See Figure 1 c).
3.2.2.4
on floor mounted
mounted on the floor
Note 1 to entry: See Figure 1 d).
3.2.2.5
under floor mounted
installed within the underframe
Note 1 to entry: See Figure 1 e).
a) roof mounted (3.2.2.1)
b) roof embedded (3.2.2.2)
c) ceiling mounted (3.2.2.3)
d) on floor mounted (3.2.2.4)
e) underfloor mounted (3.2.2.5)
Figure 1 — Diagram explaining the HVAC unit location
3.2.3 Components and parameters
3.2.3.1
air handling unit

group of components designed to move, filter and/or mix, heat and/or cool the air

Note 1 to entry: See Figure 2 to Figure 5.
3.2.3.2
compressor condenser unit
part of the HVAC unit (3.1.3.1) where heat is dissipated
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3.2.3.3
refrigerant
fluid used for heat transfer in a refrigerating circuit

[SOURCE: ISO 817:2014, 3.1.35, modified — “ system” has been replaced by “circuit”.]

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