SIST EN ISO 19424:2026

• Abstract:

  This document specifies requirements for the thermal and energy performance of refrigerated food lockers in given environmental conditions and intended for the temporary cold storage of chilled or frozen pre-ordered or pre-selected foodstuff until the final collection by the consumer.; This document also covers construction characteristics relevant for thermal and energy performance.; This document specifies tests conditions and methods for checking the requirements to be satisfied as well as the classification of refrigerated lockers, their marking and the list of characteristics to be declared by the manufacturer.; This document is not applicable to refrigerated vending machines.; It is also not applicable to:; commercial beverage coolers covered by ISO 22044;; ice cream freezers covered by ISO 22043;; refrigerated display cabinets covered by ISO 23953-1 and ISO 23953-2;; cabinets intended for storage or cabinets intended for use, e.g. in catering or non-retail refrigerated applications.; This document does not cover health and safety aspects and ergonomic principles.; The document does not cover safe storage temperatures for any specific perishable foodstuff.; The refrigeration system, providing the cooling function, is either fully or partially integrated or completely remote from the refrigerated food locker and connected by interconnecting pipe-work.

• Status: Published
• Public Enquiry End Date: 09-Oct-2025
• Publication Date: 06-Oct-2026
• ICS: 97.040.30 - Domestic refrigerating appliances
• Technical Committee: I13 - Imaginarni 13
• Current Stage: 6060 - National Implementation/Publication (Adopted Project)
• Start Date: 05-Oct-2026
• Due Date: 10-Dec-2026
• Completion Date: 07-Oct-2026
• Ref Project: EN ISO 19424:2026 - Refrigerated food lockers - Thermal and energy performance, ratings, environmental test conditions and associated testing methods (ISO 19424:2026)

Overview

SIST EN ISO 19424:2026 addresses the thermal and energy performance of refrigerated food lockers used for the temporary cold storage of chilled or frozen, pre-ordered or pre-selected foodstuff until consumer collection. This standard is relevant for manufacturers, test laboratories, retailers, and operators seeking a clear framework for performance ratings, environmental test conditions, and associated testing methods.

The document also covers construction characteristics that influence thermal and energy performance, together with requirements for classification, marking, and manufacturer declarations. It is especially useful for organizations working with refrigerated food lockers, including systems with fully integrated, partially integrated, or remote refrigeration units connected by pipe-work.

Key Topics

The standard focuses on practical performance verification for refrigerated lockers in real operating conditions. Main topics include:

• Thermal performance requirements for chilled and frozen storage zones
• Energy consumption testing under defined environmental conditions
• Environmental test classes for indoor, outdoor, and protected installations
• Construction and design characteristics that affect performance
• Classification by storage temperature
• Marking and declaration requirements from the manufacturer
• Test conditions and test room setup for repeatable assessment

It also defines testing methods for:

• Door seal effectiveness
• Physical dimensions and volumes
• Temperature performance
• Water vapour condensation
• Electrical energy consumption
• Heat extraction rate when the condensing unit is remote

The standard includes clear boundaries. It does not apply to refrigerated vending machines, commercial beverage coolers, ice cream freezers, refrigerated display cabinets, or cabinets intended for storage in catering and similar non-retail uses. It also does not cover health and safety aspects, ergonomic principles, or safe storage temperatures for specific food products.

Applications

SIST EN ISO 19424:2026 supports consistent evaluation of refrigerated food lockers across a wide range of applications, including:

• Retail and convenience pickup systems
• Click-and-collect cold storage solutions
• 24/7 consumer food collection lockers
• Indoor, outdoor, and protected outdoor installations
• Commercial refrigeration product development
• Conformity assessment and product comparison
• Manufacturer technical documentation and labeling

For businesses focused on energy-efficient refrigerated food lockers, this standard helps support product consistency and market credibility. It is also valuable for procurement teams and technical specifiers who need reliable criteria for comparing locker performance under defined climatic conditions.

Related Standards

This document is closely linked to other ISO standards for refrigerated equipment, especially:

• ISO 23953-1 - Refrigerated display cabinets - Vocabulary
• ISO 23953-2 - Refrigerated display cabinets - Classification, requirements and test conditions
• ISO 22044 - Commercial beverage coolers
• ISO 22043 - Ice cream freezers

These references help position SIST EN ISO 19424:2026 within the broader field of refrigeration performance testing and commercial refrigerated appliance standards. Together, they provide a structured basis for comparing equipment, defining test methods, and supporting compliant product development in the cold storage and food locker sector.

SLOVENSKI STANDARD
01-november-2026
Hladilne omare za živila - Toplotna in energijska učinkovitost, ocene, okoljski
preskusni pogoji in povezane preskusne metode (ISO 19424:2026)
Refrigerated food lockers - Thermal and energy performance, ratings, environmental test
conditions and associated testing methods (ISO 19424:2026)
Schließfächer mit Kühlfunktion für Lebensmittel - Thermische und energetische Leistung,
Bewertungen, Umgebungsprüfbedingungen und zugehörige Prüfverfahren (ISO
19424:2026)
Casiers réfrigérés pour aliments - Performance thermique et énergétique, évaluation,
conditions d’essai environnementales et méthodes d’essai associées (ISO 19424:2026)
Ta slovenski standard je istoveten z: EN ISO 19424:2026
ICS:
97.040.30 Hladilni aparati za dom Domestic refrigerating
appliances
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EN ISO 19424
EUROPEAN STANDARD
NORME EUROPÉENNE
September 2026
EUROPÄISCHE NORM
ICS 97.040.30
English Version
Refrigerated food lockers - Thermal and energy
performance, ratings, environmental test conditions and
associated testing methods (ISO 19424:2026)
Casiers réfrigérés pour aliments - Performance Schließfächer mit Kühlfunktion für Lebensmittel -
thermique et énergétique, évaluation, conditions Thermische und energetische Leistung, Bewertungen,
d'essai environnementales et méthodes d'essai Umgebungsprüfbedingungen und zugehörige
associées (ISO 19424:2026) Prüfverfahren (ISO 19424:2026)
This European Standard was approved by CEN on 23 August 2026.

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, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Türkiye and
United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION

EUROPÄISCHES KOMITEE FÜR NORMUNG

CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2026 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 19424:2026 E
worldwide for CEN national Members.

Contents Page
European foreword . 3

European foreword
This document (EN ISO 19424:2026) has been prepared by Technical Committee ISO/TC 86
"Refrigeration and air-conditioning" in collaboration with Technical Committee CEN/TC 44
“Commercial and Professional Refrigerating Appliances and Systems, Performance and Energy
Consumption” the secretariat of which is held by UNI.
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 March 2027, and conflicting national standards shall
be withdrawn at the latest by March 2027.
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CEN shall not be held responsible for identifying any or all such patent rights.
Any feedback and questions on this document should be directed to the users’ national standards
body/national committee. A complete listing of these bodies can be found on the CEN website.
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, Republic of
North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Türkiye and the
United Kingdom.
Endorsement notice
The text of ISO 19424:2026 has been approved by CEN as EN ISO 19424:2026 without any modification.

International
Standard
ISO 19424
First edition
Refrigerated food lockers —
2026-09
Thermal and energy performance,
ratings, environmental test
conditions and associated testing
methods
Casiers réfrigérés pour aliments — Performance thermique et
énergétique, évaluation, conditions d’essai environnementales et
méthodes d’essai associées
Reference number
ISO 19424:2026(en) © ISO 2026
ISO 19424:2026(en)
© ISO 2026
All rights reserved. Unless otherwise specified, or required in the context of its implementation, 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
CP 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Geneva
Phone: [phone]
Email: [e-mail]
Website: www.iso.org
Published in Switzerland
ii
ISO 19424:2026(en)
Contents Page
Foreword .iv
1 Scope . 1
2 Normative references . 1
3 Terms, definitions, symbols and abbreviated terms . 1
3.1 Terms and definitions .1
3.2 Symbols .3
3.2.1 General .3
3.2.2 Compression-type refrigeration systems .4
3.2.3 Indirect refrigeration-type systems .4
4 Requirements . 4
4.1 General .4
4.2 Construction .4
4.3 Operating characteristics .5
4.3.1 Classification according to temperature storage .5
4.3.2 Classification according to environmental condition .5
5 Tests . 5
5.1 General .5
5.2 Tests outside or inside test room .6
5.2.1 General .6
5.2.2 Seal test for doors .6
5.2.3 Linear dimensions, areas .6
5.3 Tests inside test room .6
5.3.1 General .6
5.3.2 Test room conditions .7
5.3.3 Preparation of test locker and general test procedures .11
5.3.4 Temperature test . .21
5.3.5 Water vapour condensation test . 23
5.3.6 Electrical energy consumption test .24
5.3.7 Heat extraction rate measurement when condensing unit is remote from locker .24
6 Test report .34
6.1 General . 34
6.2 Tests outside test room . 35
6.2.1 Seal test of doors . 35
6.2.2 Linear dimensions, areas and volumes . 35
6.3 Tests inside test room . 35
6.3.1 General test conditions . 35
6.3.2 Locker preparation . . . 35
6.3.3 Temperature test . . 36
6.3.4 Water vapour condensation test . 36
6.3.5 Electrical energy consumption test . 36
6.3.6 Heat extraction rate measurement when the condensing unit is remote from
the locker .37
7 Marking . .38
7.1 Load limit. 38
7.2 Marking plate . 40
7.3 Information to be supplied by the manufacturer . 40
Annex A (normative) Net volume calculation .42
Bibliography .43

iii
ISO 19424:2026(en)
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).
ISO draws attention to the possibility that the implementation of this document may involve the use of (a)
patent(s). ISO takes no position concerning the evidence, validity or applicability of any claimed patent
rights in respect thereof. As of the date of publication of this document, ISO had not received notice of (a)
patent(s) which may be required to implement this document. However, implementers are cautioned that
this may not represent the latest information, which may be obtained from the patent database available at
www.iso.org/patents. ISO shall not be held responsible for identifying any or all such patent rights.
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation of 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 www.iso.org/iso/foreword.html.
This document was prepared by Technical Committee ISO/TC 86 Refrigeration and air-conditioning,
Subcommittee SC 7, Testing and rating of commercial refrigerated display cabinets, in collaboration with
the European Committee for Standardization (CEN) Technical Committee CEN/TC 44, Commercial and
professional refrigerating appliances and systems, performance and energy consumption, in accordance with
the Agreement on technical cooperation between ISO and CEN (Vienna Agreement).
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www.iso.org/members.html.

iv
International Standard ISO 19424:2026(en)
Refrigerated food lockers — Thermal and energy
performance, ratings, environmental test conditions and
associated testing methods
1 Scope
This document specifies requirements for the thermal and energy performance of refrigerated food lockers
in given environmental conditions and intended for the temporary cold storage of chilled or frozen pre-
ordered or pre-selected foodstuff until the final collection by the consumer.
This document also covers construction characteristics relevant for thermal and energy performance.
This document specifies tests conditions and methods for checking the requirements to be satisfied as well
as the classification of refrigerated lockers, their marking and the list of characteristics to be declared by the
manufacturer.
This document is not applicable to refrigerated vending machines.
It is also not applicable to:
— commercial beverage coolers covered by ISO 22044;
— ice cream freezers covered by ISO 22043;
— refrigerated display cabinets covered by ISO 23953-1 and ISO 23953-2;
— cabinets intended for storage or cabinets intended for use, e.g. in catering or non-retail refrigerated
applications.
This document does not cover health and safety aspects and ergonomic principles.
The document does not cover safe storage temperatures for any specific perishable foodstuff.
The refrigeration system, providing the cooling function, is either fully or partially integrated or completely
remote from the refrigerated food locker and connected by interconnecting pipe-work.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content constitutes
requirements of this document. For dated references, only the edition cited applies. For undated references,
the latest edition of the referenced document (including any amendments) applies.
ISO 23953-1, Refrigerated display cabinets — Part 1: Vocabulary
ISO 23953-2:2023, Refrigerated display cabinets — Part 2: Classification, requirements and test conditions
3 Terms, definitions, symbols and abbreviated terms
3.1 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 23953-1 and the following apply.

ISO 19424:2026(en)
ISO and IEC maintain terminology databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at https:// www .electropedia .org/
3.1.1
refrigerated food locker
locker
commercial appliance with frozen, chilled or high temperature storage temperature zones, intended for the
temporary cold storage of pre-ordered or pre-selected foodstuff until the final collection by the consumer
Note 1 to entry: Refrigerated food lockers are foreseen for constant operation and are located inside or outside a
building or under a specific weather protection which is not part of the refrigerated food locker.
Note 2 to entry: The refrigeration system, providing the cooling function, is either fully or partially integrated or
completely remote from the refrigerated food locker and connected by interconnecting pipe-work.
Note 3 to entry: A refrigerated food locker consists of a single or multiple separated cold storage compartments with
frozen, chilled, high temperature or switchable storage temperature zones, see Table 1.
Note 4 to entry: Compartments are thermally insulated and access to the foodstuff is via a locked door or locked
opening(s).
Note 5 to entry: The loading of the refrigerated food locker with the foodstuff is executed by professional personnel
from the operator either from the front or back and self-served by the consumer from the front.
3.1.2
installation
assembly of compartments, lockers, refrigerating system and all the apparatus necessary for their operation,
which can be connected on-site to make a complete system
3.1.3
protected installation
installation specifically designed for outdoor locations and capable of operating under specific range of
outdoor conditions, in accordance with the information provided in the manufacturer’s instructions
Note 1 to entry: Typically, a protected installation is sheltered by an incomplete enclosure which includes one or
more walls and a roof. The roof typically projects on the front side of the installation for a length which guarantees
protection from dripping water with a maximum tilt angle of 15 °, see Figure 1.
Figure 1 — Protected installation
3.1.4
indoor location
enclosed room or space inside a building, with controlled or uncontrolled environmental conditions
3.1.5
outdoor location
location outside of any building or structure, exposed to the external ambient, with no protection

ISO 19424:2026(en)
3.1.6
net volume
storage volume inside the appliance which can be used for storage of products
Note 1 to entry: Net volume shall be calculated in accordance with Annex A.
3.2 Symbols
3.2.1 General
t running time, expressed in h
run
t stopping time, expressed in h
stop
t defrost time, expressed in h
deft
q mass flow rate of liquid refrigerant or secondary refrigerant, expressed in kg/s
m
Δt time between two consecutive measuring samples, expressed in h
N number of measuring samples, expressed in 24 h
max
Φ heat extraction rate during a whole day, expressed in kW
Φ heat extraction rate during a whole day excepting defrost time, expressed in kW
24-deft
E pumping electrical energy consumption, expressed in kWh
CPEC,24 h
E direct daily electrical energy consumption, expressed in kWh
DEC,24 h
E heat removal energy consumption, expressed in kWh
HREC
E lighting energy consumption, expressed in kWh
LEC
E refrigeration electrical energy consumption, expressed in kWh
REC, 24 h
E refrigeration electrical energy consumption compression-type, expressed in kWh
REC-RC,24 h
E refrigeration electrical energy consumption indirect, expressed in kWh
REC-RI,24 h
E specific daily electrical energy consumption, expressed in kWh/m
SEC
E total energy consumption, expressed in kWh
TEC
t relative or percentage running time:
rr
t t
run run
t  
rr
tt 24t
runstop deft
where
tt t 24
runstopdeft
Φ instant heat extraction rate, expressed in kW
n
V net volume
N
ISO 19424:2026(en)
3.2.2 Compression-type refrigeration systems
h , h specific enthalpy, expressed in kJ/kg, where state at point 8 corresponds to refrigerant outlet,
8 4
and state at point 4 to refrigerant inlet, of locker
θ evaporating temperature, calculated as the average of θ and θ obtained from pressure p8
mrun dew bub
and averaged over the t period, expressed in °C
run
T = θ + 273,15, expressed in K
mrun mrun
3.2.3 Indirect refrigeration-type systems
θ secondary fluid temperature at locker inlet, expressed in °C
i
θ secondary fluid temperature at locker outlet, expressed in °C
o
θ secondary fluid median temperature, expressed in °C (θ + θ )/2
i o
θ arithmetic average of the secondary fluid median temperature (θ) during t , expressed in °C
mrun run
q instant value of the secondary fluid mass flow during t , expressed in kg/s
L run
c specific heat of secondary fluid, expressed in kJ/(kg · K), at locker inlet
i
c specific heat of the secondary fluid, expressed in kJ/(kg · K), at locker outlet
o
p − p pressure drop between inlet and outlet of locker during t , expressed in kPa
irun orun run
v specific volume of secondary fluid, expressed in m /kg
(simplification: v = constant = 0,001 m /kg)
4 Requirements
4.1 General
The installation can be indoor or outdoor. In case of outdoor installation, a protected installation shall have
the following characteristics:
— avoid direct sun radiation 1 m of shadow;
— protect from rain;
— protect from dust;
— protect from wind;
— protect from snow loading (for the food locker itself) shall be taken into account 20 kg/m for outdoor
installation.
4.2 Construction
The locker and its parts shall be constructed for normal conditions of handling, transport and use. The
following requirements apply:
a) Interior fittings, including shelves, baskets, rails, etc. and their supports, shall withstand the loads for
the intended use.
b) Where sliding shelves, baskets, trays or drawers are fitted they shall retain their shape and ease of
movement when fully loaded.
ISO 19424:2026(en)
c) Any fitments which are provided with stops to prevent accidental removal shall be self-supporting when
fully loaded and withdrawn to the limit of the stops.
4.3 Operating characteristics
4.3.1 Classification according to temperature storage
The performance of lockers shall be in conformity with one of the classifications defined in Table 1. The
performance shall be verified in accordance with the conditions and test methods specified in Clause 5.
Table 1 — M-package temperature classes
Highest temperature, θ , of Lowest temperature, θ , of Lowest temperature, θ ,
ah b al
warmest M-package less than coldest M-package greater of warmest M-package
or equal to than or equal to less than or equal to
Class
(see Figure 9) (see Figure 9) (see Figure 9)
°C
L1 −15 — −18
M1 +5 −1 —
HT +20 +10 —
AF — + 5 —
Key
L1 Frozen temperature class
M1 Chilled temperature class
HT High temperature class
AF antifreeze class
4.3.2 Classification according to environmental condition
Outdoor installation requires that the manufacturer state the maximum as well as the minimum
environmental classes that the appliance is capable of sustaining with no changes.
Test for a winter condition shall be verified in a cold room, in one of the conditions listed in Table 3 according
to the relevant test of Clause 5.
Classes intended to simulate outdoor winter conditions are specified in Table 3 with a negative value for test
room climate class.
5 Tests
5.1 General
When the characteristics of a locker are to be verified, all the tests shall be applied to the same refrigerated
food locker.
All compartments within the locker shall be tested according to the declared temperature classification.
If the locker is capable of operating at different temperature classification., tests shall be carried out at each
classification. Tests shall be carried out for each declared performance within the classes defined in Table 1.
If a locker compartment is specified for multiple product temperature classification, the lowest temperature
is used for testing of temperature performances (5.3.4) and energy consumption (5.3.6).
Lockers shall comply with the requirements specified in Clause 4 using the appropriate test method as
described in Table 2.
ISO 19424:2026(en)
Table 2 — Test summary
Tests Requirement clause Test method Test location
Seal test 4.1 5.2.2 Outside or inside
test room
Physical dimensions 4.2 5.2.3
(see 5.2)
Temperature 4.3 5.3.4
Defrosting 4.3 5.3.4
Inside test room
Water vapour condensation 4.3 5.3.5
(see 5.3)
Energy consumption 4.3 5.3.6
Heat extraction rate 4.3 5.3.7
5.2 Tests outside or inside test room
5.2.1 General
The tests that deal with the inspection of construction characteristics and physical dimensions may be
carried out outside the test room.
5.2.2 Seal test for doors
The effectiveness of doors provided to ensure a seal shall be tested as follows (with the locker not running).
Insert a strip of paper 50 mm wide, 0,08 mm thick and of a suitable length at any point of the seal.
The strip of paper shall not slide freely when the door is closed normally.
NOTE 1 Some lockers that have doors to ensure an air seal are fitted with decompression valves which allow air to
penetrate for a short period of time so that any drop in pressure created inside the locker is compensated. No test is
required for such valves.
NOTE 2 The most unfavourable points can be found by inspecting the contact of the seal with the locker closed and
lit from the inside.
5.2.3 Linear dimensions, areas
Measurements shall be made with the locker not in operation but situated in a place where the temperature
is maintained between 16 °C and 30 °C.
For lockers that have detachable ends, overall dimensions are given with and without ends. If the locker
includes jacks or other components for adjusting height, the height defined shall be the minimum height
necessary at installation of the locker.
5.3 Tests inside test room
5.3.1 General
The tests which are carried out inside the test room deal with the assessment of the following characteristics:
— temperature;
— defrosting effect;
— water vapour condensation;
— electrical energy consumption;
— heat extraction rate (only for lockers with remote unit).

ISO 19424:2026(en)
These measurements should be made simultaneously.
5.3.2 Test room conditions
5.3.2.1 General
Subclauses 5.3.2.2, 5.3.2.3 and 5.3.2.4 define general testing conditions which are common for all tests
specified in 5.3.4 to 5.3.7 carried out inside the test room. These conditions concern the test room, the test
and M-packages and the measuring instruments.
A test room that conforms to ISO 23953-2:2023, 5.3.2.2 shall be used except when testing in winter condition
as identified in Table 3.
5.3.2.2 Test room: General design, walls, floor and radiant heat
The test room shall be a parallelepiped space in which two of the opposite side walls, referred to as the
"discharge technical side wall" and the "return technical side wall", are designed to create an even,
horizontal air flow within the test room. By convention, the distance separating these two technical side
walls is referred to as the length of the test room.
The minimum useful dimensions (length, width, height) of the test room shall be dependent on the overall
dimensions (length, depth, height) of the refrigerated food locker to be tested and on the location of the
opening of the locker (see 5.3.3.1).
The ceiling and the two non-technical side walls of the room shall be thermally insulated and shall be
equipped with an inner metal skin.
For winter conditions identified in Table 3, the following apply:
— The size of the room shall be no less than 20 m and with the appliance placed in the middle with a
minimum of 1 m of free space surrounding the appliance.
— The room height shall be at least 1 m higher than the maximum height of the appliance.
A minimum insulation level equivalent to 60 mm of rigid polyurethane foam (λ = 0,03 W/m °C) should be
used for the building of a new test room.
The floor shall be made either of concrete or of thermally equivalent material and shall be sufficiently
insulated to ensure that external climatic conditions do not affect the floor temperature.
Lighting shall be installed to maintain 600 ± 100 lx measured at a height of 1 m above the floor level and
shall be lit continuously during the test period. The emission spectrum of that lighting device within the
infrared field shall not include peaks of a value of more than 500 W/5 nm/lm.
The walls, ceilings and any partitions of rooms intended for the testing of lockers shall be painted in light
grey (e.g. NCS 2706-G90Y or RAL 7032) so that the emissivity is between 0,9 and 1 at 25 °C.
5.3.2.3 Test room (empty): Thermal and air flow characteristics
An experimental evaluation of the test-room performances shall be carried out minimum once per year
under the following conditions:
— with test room empty and with lighting switched on;
— in a test-room climate class 3 (see Table 3);
— measuring the velocity, temperature and relative humidity of the air at different points of two vertical
planes parallel to the technical side walls and 600 mm away from the technical side walls;
— with the climate measuring point located at the geometrical centre of the test room during this evaluation.

ISO 19424:2026(en)
These measuring points shall form a two-dimensional grid in which the step is a maximum of 500 mm in the
horizontal and vertical directions. The peripheral line of points shall be located at a maximum of 500 mm
from the other two side walls, floor and ceiling.
Obstacles or irregularities projected into the room of more than 1 m surface area facing the discharge
technical side wall can exist along the walls. In this case, a three-dimensional grid inside the test room shall
be investigated.
The mean horizontal air velocity measured during 1 min with a maximal interval of 5 s at each of the
measuring points shall lie between 0,1 m/s and 0,2 m/s.
Air temperature measured at each of the measuring points shall not deviate from the rated temperature of
the test-room climate class by more than 2 °C.
The test room shall be capable of maintaining values of humidity within ±3 units of the relative humidity
percentage figures of the rated humidity of the test room temperature class at the specified measuring
points.
The surface temperature of the walls, ceiling and floor shall be measured in proximity to the points which
constitute the peripheral line of the grid. These surface temperatures shall remain within a tolerance of
±2 °C in relation to the air temperature measured at the nearest point of the grid.
5.3.2.4 Test room climate definition
5.3.2.4.1 Test room climate classes
Tests shall be carried out in at least one of the climate classes defined in Table 3.
During the test, the test room shall be capable of maintaining values of temperature and humidity within
±1 °C of the temperature and ±5 units of the relative humidity percentage figures at the specified climate
measuring point(s) (see 5.3.2.4.2). The exception to this is test room climate class 3, for which the tolerance
of the relative humidity is ±3 units.
When testing at climate classes −3, −2 and −1, the test room shall be capable of maintaining the temperature
within ±2 °C at the climate measuring point(s). When testing at climate classes −3, −2 and −1, the relative
humidity is not relevant.
Table 3 — Climate classes
Dry bulb tempera- Water vapour mass
Relative humidity Dew point
Test room climate
ture in dry air
class
°C % °C g/kg
−3 −22 Not relevant Not relevant −
−2 −7 Not relevant Not relevant −
−1 +5 Not relevant Not relevant −
0 20 50 9,3 7,3
1 16 80 12,6 9,1
8 24 55 14,4 10,2
2 22 65 15,2 10,8
3 25 60 16,7 12,0
4 30 55 20,0 14,8
NOTE 1 The water vapour mass in dry air is one of the main points that influences the performance and energy consumption of
the lockers. Therefore, the order of the climate class in the table is based on the water vapour mass column.
NOTE 2 Classes with a negative test room climate class are intended to simulate outdoor winter conditions.

ISO 19424:2026(en)
TTaabbllee 33 ((ccoonnttiinnueuedd))
Dry bulb tempera- Water vapour mass
Relative humidity Dew point
Test room climate
ture in dry air
class
°C % °C g/kg
6 27 70 21,1 15,8
5 40 40 23,9 18,8
7 35 75 30,0 27,3
NOTE 1 The water vapour mass in dry air is one of the main points that influences the performance and energy consumption of
the lockers. Therefore, the order of the climate class in the table is based on the water vapour mass column.
NOTE 2 Classes with a negative test room climate class are intended to simulate outdoor winter conditions.
5.3.2.4.2 Climate measuring point
The point for measuring ambient temperature and relative humidity shall be placed 300 mm upstream
towards the test room air supply wall in accordance with the plan view in Figure 2 and the section view in
Figure 3.
The warm condenser air flow shall be prevented from influencing the temperature at the measuring point
by air deflectors or other suitable means (see Figure 4 and Figure 5).
Dimensions in millimetres
Key
1 room air flow
2 locker
3 back
4 front
Figure 2 — Plan of climate measuring point

ISO 19424:2026(en)
Dimensions in millimetres
Figure 3 — Climate measuring point for one typical example
5.3.2.4.3 Test packages and life-time
Measurement test packages, where foreseen, shall conform to ISO 23953-2:2023, 5.3.2.5, 5.2.3.6 and 5.3.2.7.
5.3.2.4.4 Instruments, measuring equipment and measuring accuracy
All measurements shall be carried out with instruments that have been calibrated.
Temperature measurements shall be made to an accuracy of ±0,8 °C. Climate temperatures shall be measured
by sensors, inserted in the centre of tinned solid copper or copper-zinc alloy cylinders having a mass of 25 g
and of minimum external area (diameter = height = approximately 12,5 mm).
When testing a locker intended for connection to an indirect type refrigerating system, temperature
difference in secondary fluids shall be measured to an accuracy of ±0,1 °C (see 5.3.7.2.2).
Illumination flux per square metre shall be measured to an accuracy of ±10 %.
Pressures shall be measured to an accuracy of ±1 %.
Relative humidity shall be measured to an accuracy of ±3 units of the percentage figure.
Electrical energy consumption shall be measured to an accuracy of ±2 % (see 5.3.6).

ISO 19424:2026(en)
Time interval measurements shall be made to an accuracy of ±1 % or better. All the temperatures are
checked every 60 s.
The time interval for the measurements of refrigerant mass flow rate, inlet/outlet temperature and inlet
and suction pressure shall be less than or equal to 20 s (see 5.3.7.2).
In the case of electronic expansion valves, measurements shall be sampled at a rate to avoid undersampling
due to the periodic openings of the valve.
NOTE According to the Nyquist-Shannon sampling theorem, undersampling means sampling a periodic signal
with a frequency below 2 times the frequency of the signal itself.
Air velocity shall be measured using a laboratory-type instrument with an accuracy of 10 % or ±0,03 m/s,
whichever is the greater, and with a minimum sensitivity of 0,03 m/s in the range of 0 m/s to 1,5 m/s in
horizontal flow at the temperature of the selected ambient class.
Mass flow rate shall be measured to an accuracy of ±1 % during the t period of operation of the locker
run
(see 5.3.7).
5.3.3 Preparation of test locker and general test procedures
5.3.3.1 Locker selection, installation and positioning within the test room
Each locker intended to be tested, unless a prototype, shall be selected from stock or routine production and
shall be representative as to construction and adjustment.
The locker, including all components required for normal operation, shall be assembled, set up and sited as
it would be installed in service as far as practicable and in accordance with the manufacturer's instructions.
All permanently located accessories required for normal use shall be in their respective places.
The locker shall be located as follows (see Figure 4):
— X = 2 m and B ≥ 1 m for all other lockers;
— Y ≥ 0,8 m for horizontal lockers, vertical lockers;
— A ≥ 0,8 m;
— A = Y should be used when A ≥ 1,5 m;
— C ≥ height of locker +0,5 m (for vertical lockers).
The locker shall be located within the test room perpendicularly to the two technical side walls in such
a way that the distances A (and respectively Y) measured at the two ends of the locker are equal with a
tolerance of ±4 mm for each meter of length of the locker.
For lockers intended to be placed against a wall, and in order to check the running of lockers with the
incorporated condensing unit correctly according to 5.3.2 or the water vapour condensation according to
5.3.4, a vertical partition shall be placed either against the rear of the locker or at a distance d from the rear
p
as specified by the manufacturer (see Figure 4).
The distance, d , between the back of the locker and the vertical panel shall be specified by the manufacturer
p
(see Figure 4). Where this is not specified, the locker shall be tested with the partition placed against the
rear of the locker, i.e. distance d = 0.
p
ISO 19424:2026(en)
Dimensions in millimetres
Key
X distance from the test room air discharge wall
Y distance from the test room front wall
d partition distance specified by the manufacturer
p
1 technical side wall — test room air discharge
2 technical side wall — test room air return
3 vertical partition for wall site locker with same length and height as locker
A distance from the test room back wall
B distance from the test room air return wall
C height of the test room
a
Air currents parallel to the plane of the opening (in longitudinal direction)
Figure 4 — Locker location within test room
The air movement of the test room shall be parallel to the longitudinal axis according to 5.3.3.2.
The direction of the warm condenser airflow should be the same as the test room air flow direction and not
opposed to it.
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