COP stands for coefficient of performance and is a measurement of efficiency for heating and cooling machines. It is measured by the total energy output (kw) that is leaving the unit in forms of heating or cooling over the total energy input (kW) that is entering the unit in forms of electricity. The higher COP, the more efficient a unit is and we are proud to say that our units are remarkable for their high COPs of 6.5 to 10 on average.  This means 1kW of energy input yields 6.5-10kW of heating output.