ISO 50002-3:2025
(Main)Energy audits — Part 3: Guidance for conducting an energy audit using ISO 50002-1 in processes
Energy audits — Part 3: Guidance for conducting an energy audit using ISO 50002-1 in processes
This document gives guidance on how to apply ISO 50002-1 to carry out energy audits of a process. It is intended to be used in conjunction with, and is supplementary to, ISO 50002-1. If buildings are included in the scope of the energy audit, the energy auditor can choose to apply ISO 50002-2.
Audits énergétiques — Partie 3: Recommandations pour la conduite d'un audit énergétique selon l'ISO 50002-1 dans des processus
General Information
Relations
Standards Content (Sample)
International
Standard
ISO 50002-3
First edition
Energy audits —
2025-06
Part 3:
Guidance for conducting an
energy audit using ISO 50002-1 in
processes
Audits énergétiques —
Partie 3: Recommandations pour la conduite d'un audit
énergétique selon l'ISO 50002-1 dans des processus
Reference number
© ISO 2025
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ii
Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Principles of energy auditing . 2
5 Performing an energy audit . 2
5.1 General .2
5.2 Planning .2
5.3 Opening meeting .3
5.4 Data collection .3
5.5 Measurement plan .4
5.5.1 General .4
5.5.2 Preliminary data analysis .4
5.5.3 Data measurement plan .4
5.6 Site visit . .5
5.6.1 Site visits .5
5.6.2 Management of field work .5
5.7 Analysis .5
5.7.1 General .5
5.7.2 Analysis of current energy performance .5
5.7.3 Identification of energy performance improvement opportunities .6
5.7.4 Evaluation of energy performance improvement opportunities .7
5.8 Reporting .7
5.8.1 General .7
5.8.2 Report content .7
5.9 Closing meeting .7
6 Competence of the energy auditor . 7
Annex A (informative) Data which can be collected . 8
Annex B (informative) Quality of measurement plan .15
Annex C (informative) Representative energy sampling approach for multi-site organizations . 17
Bibliography . 19
iii
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
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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 document 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
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This document was prepared by Technical Committee ISO/TC 301, Energy management and energy savings.
A list of all parts in the ISO 50002 series can be found on the ISO website.
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
Introduction
An energy audit can help an organization identify opportunities to improve energy performance. It can be
part of a site-wide energy management system (EnMS). This document provides guidance for conducting an
ISO 50002-1-based energy audit of processes.
There are many types of processes in industry and commerce. In general, energy is used:
— directly by a process (e.g. furnaces, direct fired dryers);
— indirectly by a process (e.g. heat exchange, distillation, extrusion), including the specific conditions of
production (e.g. start-up, shut-down, product change over, cleaning, maintenance, laboratory and product
transfer);
— directly by a commercial organization, (e.g. meal preparation process, TV broadcasting process, data
centre process, coffee roasting);
— utility processes (e.g. motor driven systems (fans, pumps, motors, compressors, etc.), steam, hot water),
including on-site power plants;
— product or service changeover, (e.g. change of production feed or production quality, start-up, shut down,
cleaning-in-place, sterilization);
— other processes (e.g. sterilization in hospitals, fume cupboards, laboratories).
The energy audits covered by this document may be independent from energy performance certification.
v
International Standard ISO 50002-3:2025(en)
Energy audits —
Part 3:
Guidance for conducting an energy audit using ISO 50002-1 in
processes
1 Scope
This document gives guidance on how to apply ISO 50002-1 to carry out energy audits of a process. It is
intended to be used in conjunction with, and is supplementary to, ISO 50002-1.
If buildings are included in the scope of the energy audit, the energy auditor can choose to apply ISO 50002-2.
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 50002-1, Energy audits — Part 1: General requirements with guidance for use
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 50002-1 and the following apply.
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
audit client
person or organization that commissions an energy audit
Note 1 to entry: to entry. The audit client can be the owner, operator, process licensor and/or the service provider.
3.2
process
set of interrelated or interacting activities that use inputs to deliver an intended result
Note 1 to entry: to entry. This can include one or more production lines, laboratories, research centres, packaging and
warehouse sections with specific operational conditions and site transportation. An energy audit can be conducted on
selected processes or systems in an organization or site (3.4) or on all processes in an organization or site.
3.3
production process
all the steps, or some of the steps, necessary to manufacture a product, intermediate product, by-product or
co-product, or to deliver a service
Note 1 to entry: Production process can include specific facilities for health, safety and environmental pollution
control.
3.4
site
processes (3.2) within the boundary of the organization
Note 1 to entry: This may include processes for pollution treatment, energy recovery and waste management.
3.5
utility
generation and distribution of energy necessary for the process (3.2) and auxiliary
4 Principles of energy auditing
The principles of ISO 50002-1 apply.
5 Performing an energy audit
5.1 General
The general requirements of ISO 50002-1 apply.
5.2 Planning
In processes, the audit client and the auditee can be different. Their roles and responsibilities in the process
can also be different. For example, a process can be owner operated and maintained by a single organization.
The process can also be owned, operated and maintained by different organizations.
The energy auditor should obtain a preliminary description of the site and the process from the organization
or from a site visit.
NOTE 1 The preliminary contact can
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