Fans are not only evaluated on the basis of aerodynamic and acoustic data. In recent years, the focus has increasingly shifted to the efficiency of a blower system. To evaluate the energy efficiency of products, a legislative framework has been created at EU level to establish a uniform standard within the European Union. This chapter of the punker Fan Technology Guide provides an overview of the EU Ecodesign Framework Directive and explains in detail the Implementing Regulation (EU) No. 327/2011 for fans.