The ErP Directive defines minimum energy efficiency requirements for fans placed on the European Union market. The requirements for axial fans were introduced by Commission Regulation (EU) No 327/2011, applicable since 1 January 2015 for units with input power from 0.125 kW.
The minimum energy efficiency is calculated using the formula: η_target = 2.74 × ln(P) – 6.33 + N
where:
P – electrical input power of the fan [kW]
ln(P) – natural logarithm of the power
N – efficiency coefficient depending on the measurement category and type of efficiency (static or total).
For axial fans, the N values are:
• N = 40 (measurement categories A, C – static efficiency)
• N = 58 (measurement categories B, D – total efficiency)
From 24 July 2026, the requirements defined in Commission Regulation (EU) 2024/1834 apply, increasing the minimum efficiency coefficients to:
• N = 50 (A, C – static)
• N = 64 (B, D – total)
Higher requirements mean the need to use more efficient designs and modern drive solutions. In practice, this results in lower energy consumption, reduced operating costs and compliance with current EU regulations.