In line with the European Directive 2009/125 / EC and with a view to achieving 20/20/20 environmental targets by 2020, ie -20% of primary energy use, -20% of C02 and + 20% of renewable energy sources, home air conditioning units up to 12kW (42,000 btu / h) are subject to new regulations concerning their energy characteristics. Air conditioners are products that are directly related to the environment, both because of the energy they consume in their operation and / or their standby condition, as well as the energy and raw materials required during their production as well as the transport to the destination of disposal. The European Union, by deciding to step up checks on imported products with a view always to protecting the environment and to improve the information to consumers about products placed on the market, has forced the calibration of air conditioners on the basis of a new set of rules for the evaluation of energy performance. Seasonal Energy Efficiency Ratio (SEER) and Seasonal Performance Ratio (SCOP) are considered to represent better the performance of its units throughout the year, as opposed to the previous measurement and marking, which concerned instantaneous performance. This new calibration measures the performance of air conditioners in many different conditions, unlike previous measurements that related with 1 point only.