2. COP (Coefficient Of Performance) is determined by dividing the heating output watts by the electrical power needed to run the airconditioner in heating (heating input watts). The higher the ratio number, the more energy efficient the unit is to operate. 3. Energy Rating Label shows both a unit’s star rating and also the estimated energy consumption per year. Test procedures are measured under Australian Standards. It is mandatory for all single phase reverse cycle airconditioners to carry this label when offered for sale. You can usually find these performance ratings in a unit’s specification data sheet or brochure. At Ascent Air we’ve done the comparing for you, partnering with leading brands in energy efficiency. We even have units in our range with the prestigous TESA label (Top Energy Saver Award).