SIST EN ISO 12759-4:2020/kFprA1:2026

• Status: Not Published
• Public Enquiry End Date: 30-Apr-2026
• ICS: 23.120 - Ventilators. Fans. Air-conditioners
• Technical Committee: OGS - Heating for buildings
• Current Stage: 5020 - Formal vote (FV) (Adopted Project)
• Start Date: 21-Oct-2026
• Due Date: 09-Dec-2026
• Completion Date: 22-Oct-2026
• Ref Project: EN ISO 12759-4:2019/FprA1:2026 - Fans - Efficiency classification for fans - Part 4: Driven fans at maximum operating speed - Amendment 1 (ISO 12759-4:2019/FDAmd1:2026)

• Amends: SIST EN ISO 12759-4:2020 - Fans - Efficiency classification for fans - Part 4: Driven fans at maximum operating speed (ISO 12759-4:2019)
• Effective Date: 07-May-2025

SIST EN ISO 12759-4:2020/kFprA1:2026 is a draft amendment to the fan efficiency classification standard for driven fans at maximum operating speed. It adds an informative Annex F with an example of how efficiency classification can be used to set minimum efficiency limits (MELs), and it makes editorial updates to the existing text. The document is relevant to engineers, test laboratories, manufacturers and compliance staff who classify fan efficiency or apply ecodesign-oriented limits.

What does SIST EN ISO 12759-4:2020/kFprA1:2026 specify?

SIST EN ISO 12759-4:2020/kFprA1:2026 specifies a system for classifying fan efficiency for all fan types driven by motors with an electrical input power of 0.125 kW and above. It applies to driven fans as products, not to the complete equipment or ventilation system in which they may be installed.

The amendment revises the scope text, updates key definitions in clause 3, adjusts the installation-category references in clause 5.2, and adds informative Annex F before the bibliography.

Annex	What it covers
F (informative)	An example of using efficiency classification to set MELs for fans driven by motors with an electrical input power between 125 W and 500 kW, including limit curves and correction factors.

What are the key requirements of SIST EN ISO 12759-4:2020/kFprA1:2026?

SIST EN ISO 12759-4:2020/kFprA1:2026 keeps the efficiency classification tied to defined power inputs, installation categories and a worked example for MEL setting. For users, the main task is to apply the right definition and test basis before comparing fan efficiency results.

• The scope limits the document to driven fans with motors at or above 0.125 kW, and it treats the fan separately from the system in which it is installed. In practice, this means the standard is used for the fan product itself, not for the full ventilation assembly.
• The document and the companion parts ISO 12759-3, ISO 12759-5 and ISO 12759-6 are described as providing different procedures to classify fan efficiency or apply MELs. In practice, users need to select the procedure that matches the intended classification or regulatory route.
• Clause 3 updates the definitions for fan air power and fan static air power when a variable speed drive is involved. In practice, this matters because the efficiency calculation depends on the correct power basis and the correct drive/control input power.
• Clause 5.2 links the four installation categories to ISO 5801:2017, with categories A, B, C and D aligned to its installation types. In practice, the test set-up category has to be chosen consistently before efficiency values are compared.
• Annex F gives an informative example for ecodesign use with fans driven by motors between 125 W and 500 kW, including axial, forward curved centrifugal, radial, mixed flow, and centrifugal backward bladed fans with and without housing. In practice, it shows how measured performance can be turned into a minimum-efficiency limit application.
• Annex F also introduces correction factors for power conversion, part-load conditions and protective guards. In practice, these factors change the calculated efficiency when the fan has a DC motor, a variable speed drive, or a permanently fitted guard.

What terms does SIST EN ISO 12759-4:2020/kFprA1:2026 define?

• MEL - minimum efficiency limit, the limit used when setting a minimum acceptable fan efficiency.
• Fan air power - conventional output power based on mass flow and fan static work, or on inlet volume flow, compressibility coefficient and fan static pressure.
• Fan static air power - the static version of fan output power used in the efficiency definition for a fan and motor combination with a variable speed drive.
• Drive/control electrical input power - the electrical input power used in the efficiency calculation for a fan and motor combination with a variable speed drive.
• Drive/control input power - the input power referenced by note 3 to 3.26.
• Category A / B / C / D installation - the installation classes used in clause 5.2 and tied to ISO 5801:2017.

Who uses SIST EN ISO 12759-4:2020/kFprA1:2026?

SIST EN ISO 12759-4:2020/kFprA1:2026 is used by people who design, test, specify or assess fans and ventilation equipment.

• Fan manufacturers use it to classify products and support efficiency claims.
• Test laboratories use it to choose the installation category and calculate results consistently.
• HVAC and ventilation designers use it when selecting fan types for systems.
• Ecodesign and compliance teams use Annex F when checking MEL-related applications.
• Buyers and quality managers use it to compare supplier data on the same efficiency basis.

What changed in SIST EN ISO 12759-4:2020/kFprA1:2026 from the previous edition?

This amendment to ISO 12759-4:2019 makes the following changes:

• adds Annex F with an example of using efficiency classification to set MELs;
• makes editorial changes to the document;
• revises the scope text;
• updates clause 3.17;
• updates clause 3.26 and note 3 to 3.26;
• updates clause 3.28;
• replaces the four bullets in clause 5.2 with references to ISO 5801:2017 categories A, B, C and D;
• adds Commission Regulation (EU) 2024/1834 to the bibliography.

Which standards are used with SIST EN ISO 12759-4:2020/kFprA1:2026?

Standard	Contribution
ISO 12759-3	Named as a companion part that also describes procedures for classifying fan efficiency or applying MELs.
ISO 12759-5	Named as a companion part that also describes procedures for classifying fan efficiency or applying MELs.
ISO 12759-6	Named as a companion part that also describes procedures for classifying fan efficiency or applying MELs.
ISO 5801:2017	Provides the installation categories used in clause 5.2.
ISO 13857:2019	Defines the opening dimension e used for the guard compensation factor in Annex F.

What does the SIST EN ISO 12759-4:2020/kFprA1:2026 document contain?

SIST EN ISO 12759-4:2020/kFprA1:2026 contains revised scope wording, updated efficiency definitions and an informative annex with a worked application example. The annex gives equation-based limit curves and correction factors for ecodesign use, without reproducing the full regulatory text.

It also links the test installation categories to ISO 5801:2017 and updates the power definitions used in the efficiency calculations. For users, that means the document is mainly about applying the right method, test basis and correction factors when classifying fan efficiency.

SLOVENSKI STANDARD
SIST EN ISO 12759-4:2020/oprA1:2026
01-april-2026
Ventilatorji - Klasifikacija učinkovitosti ventilatorjev - 4. del: Ventilatorji s pogonom
pri največji obratovalni hitrosti - Dopolnilo A1: Dodatek Priloge F, ki vsebuje
primer uporabe razvrstitve učinkovitosti in uredniške spremembe (ISO 12759-
4:2019/DAM 1:2026)
Fans - Efficiency classification for fans - Part 4: Driven fans at maximum operating speed
- Amendment 1: Addition of Annex F providing an example of the use of efficiency
classification and editorial changes (ISO 12759-4:2019/DAM 1:2026)
Ventilatoren - Effizienzklassifizierung für Ventilatoren - Teil 4: Angetriebene Ventilatoren
bei maximaler Betriebsdrehzahl (ISO 12759-4:2019/DAM 1:2026)
Ventilateurs - Classification du rendement des ventilateurs - Partie 4: Ventilateurs
entraînés à vitesse maximale de fonctionnement - Amendement 1: Ajout de l'annexe F
fournissant un exemple d'utilisation de l'efficacité et de modifications rédactionnelles
(ISO 12759-4:2019/DAM 1:2026)
Ta slovenski standard je istoveten z: EN ISO 12759-4:2019/prA1
ICS:
23.120 Zračniki. Vetrniki. Klimatske Ventilators. Fans. Air-
naprave conditioners
SIST EN ISO 12759-4:2020/oprA1:2026 en,fr,de
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

SIST EN ISO 12759-4:2020/oprA1:2026

SIST EN ISO 12759-4:2020/oprA1:2026
DRAFT
Amendment
ISO 12759-4:2019/
DAM 1
ISO/TC 117
Fans — Efficiency classification for
Secretariat: BSI
fans —
Voting begins on:
Part 4:
2026-02-16
Driven fans at maximum operating
Voting terminates on:
speed 2026-05-11
AMENDMENT 1: Addition of Annex
F providing an example of the use of
efficiency classification and editorial
changes
ICS: 23.120
THIS DOCUMENT IS A DRAFT CIRCULATED
FOR COMMENTS AND APPROVAL. IT
IS THEREFORE SUBJECT TO CHANGE
AND MAY NOT BE REFERRED TO AS AN
INTERNATIONAL STANDARD UNTIL
PUBLISHED AS SUCH.
This document is circulated as received from the committee secretariat.
IN ADDITION TO THEIR EVALUATION AS
BEING ACCEPTABLE FOR INDUSTRIAL,
TECHNOLOGICAL, COMMERCIAL AND
USER PURPOSES, DRAFT INTERNATIONAL
STANDARDS MAY ON OCCASION HAVE TO
ISO/CEN PARALLEL PROCESSING
BE CONSIDERED IN THE LIGHT OF THEIR
POTENTIAL TO BECOME STANDARDS TO
WHICH REFERENCE MAY BE MADE IN
NATIONAL REGULATIONS.
RECIPIENTS OF THIS DRAFT ARE INVITED
TO SUBMIT, WITH THEIR COMMENTS,
NOTIFICATION OF ANY RELEVANT PATENT
RIGHTS OF WHICH THEY ARE AWARE AND TO
PROVIDE SUPPORTING DOCUMENTATION.
Reference number
ISO 12759-4:2019/DAM 1:2026(en)

SIST EN ISO 12759-4:2020/oprA1:2026
DRAFT
ISO 12759-4:2019/DAM 1:2026(en)
Amendment
ISO 12759-4:2019/
DAM 1
ISO/TC 117
Fans — Efficiency classification for
Secretariat: BSI
fans —
Voting begins on:
Part 4:
Driven fans at maximum operating
Voting terminates on:
speed
AMENDMENT 1: Addition of Annex
F providing an example of the use of
efficiency classification and editorial
changes
ICS: 23.120
THIS DOCUMENT IS A DRAFT CIRCULATED
FOR COMMENTS AND APPROVAL. IT
IS THEREFORE SUBJECT TO CHANGE
AND MAY NOT BE REFERRED TO AS AN
INTERNATIONAL STANDARD UNTIL
PUBLISHED AS SUCH.
This document is circulated as received from the committee secretariat.
IN ADDITION TO THEIR EVALUATION AS
BEING ACCEPTABLE FOR INDUSTRIAL,
© ISO 2026
TECHNOLOGICAL, COMMERCIAL AND
USER PURPOSES, DRAFT INTERNATIONAL
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
STANDARDS MAY ON OCCASION HAVE TO
ISO/CEN PARALLEL PROCESSING
be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on
BE CONSIDERED IN THE LIGHT OF THEIR
the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address below
POTENTIAL TO BECOME STANDARDS TO
WHICH REFERENCE MAY BE MADE IN
or ISO’s member body in the country of the requester.
NATIONAL REGULATIONS.
ISO copyright office
RECIPIENTS OF THIS DRAFT ARE INVITED
CP 401 • Ch. de Blandonnet 8
TO SUBMIT, WITH THEIR COMMENTS,
CH-1214 Vernier, Geneva
NOTIFICATION OF ANY RELEVANT PATENT
Phone: [phone]
RIGHTS OF WHICH THEY ARE AWARE AND TO
PROVIDE SUPPORTING DOCUMENTATION.
Email: [e-mail]
Website: www.iso.org
Published in Switzerland Reference number
ISO 12759-4:2019/DAM 1:2026(en)

ii
SIST EN ISO 12759-4:2020/oprA1:2026
ISO 12759-4:2019/DAM 1:2026(en)
Foreword
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This document was prepared by Technical Committee ISO/TC 117, Fans.
A list of all parts in the ISO 12759 series can be found on the ISO website.
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