The efficiency test standard FprEN 17166 "Fans – Procedures and methods to determine the energy efficiency for the electric input power range of 125 W to 500 kW" was developed at the request of the European Commission. It was requested to support regulation 327/2011 ecodesign requirements for fans driven by motors with electric input power between 125 W and 500 kW. In drafting the standard, technical experts of the technical committee CEN TC156 WG17 took the opportunity to create new terms and definitions to clarify issues that occurred with the publication of the regulation. But some aspects had to follow the legally binding requirements of the regulation leaving unresolved matters. The request in the European Commission annual Union work programme for European standardisation for 2021 gives an opportunity to put right those problems and provides an opportunity to further improve the system approach. The industry and other stakeholders should carefully consider what needs to be in the Standardisation Request (sReq) that will be the basis of the Commission’s instruction to CEN TC156 WG17. The European Ventilation Industry Association (EVIA) is being proactive with a proposal. Prior to FprEN17166, significant elements of the fan that are necessary to determine the performance were taken for granted. Fan engineers knew what was required, but not every element was defined. Some terms and definitions were missing from standards, and others unexpectedly interpretation. This resulted in misunderstanding and products being within the scope of the regulation, but without methods to determine the energy performance. The draft standard is close to being a desired system approach. A revision can put in place the requirements to provide integrators and users with information to make better informed decisions. Those requirements can include a common method to determine, publish and interpolate data across the complete operating range including partial load. Standards for motors and VSD have, and are in the process of, being revised to provide methodologies to determine the performance and losses at any operating point. A revision of the fan standard will provide an opportunity to incorporate those methods and to define when calculation methods are appropriate. The Fan working group of EVIA has defined the problems of aspects of the ecodesign fan regulation, listened to the requests of other stakeholders for revised standardisation and has made a proposal for change to the Commission. This paper describes those proposals.