The request for a revision, or new fan efficiency standard, in the European Commission annual Union work programme for European standardisation for 2022 is specific in its requirements for ‘an extended products approach, notably by defining a sufficient number of operating points and an interpolation/calculation method and/or a characteristic curve’.
The source of the request for ‘a sufficient number of operating points and an interpolation/ calculation method’ can be found in criticism from several stakeholders, including the consultant acting on behalf of the commission.
This is explained in detail in the Problem Statement published by the European Ventilation Industry Association (EVIA). ...