The purpose of this Eurovent standard is to define energy efficiency for mechanical draught evaporative cooling products, determine target levels with the aim to improve the energy efficiency of the population of mechanical draught evaporative cooling products within Europe and the Middle East over a period of time, and define the methods to be applied by suppliers to verify that the defined efficiency targets are actually met. Eurovent 9/12 applies to mechanical draught evaporative cooling products, which transfer heat of the atmosphere primarily by the evaporation of water (latent heat transfer). Mechanical draught evaporative products include open wet cooling towers as well as closed-circuit cooling towers and evaporative condensers in the forced and the induced draught configuration using either axial or centrifugal fans.