<Table> <Tr> <Td> </Td> <Td> This article possibly contains original research . Please improve it by verifying the claims made and adding inline citations . Statements consisting only of original research should be removed . (September 2012) (Learn how and when to remove this template message) </Td> </Tr> </Table> <Tr> <Td> </Td> <Td> This article possibly contains original research . Please improve it by verifying the claims made and adding inline citations . Statements consisting only of original research should be removed . (September 2012) (Learn how and when to remove this template message) </Td> </Tr> <P> The coefficient of performance or COP (sometimes CP or CoP) of a heat pump, refrigerator or air conditioning system is a ratio of useful heating or cooling provided to work required . Higher COPs equate to lower operating costs . The COP usually exceeds 1, especially in heat pumps, because, instead of just converting work to heat (which, if 100% efficient, would be a COP_hp of 1), it pumps additional heat from a heat source to where the heat is required . For complete systems, COP calculations should include energy consumption of all power consuming auxiliaries . COP is highly dependent on operating conditions, especially absolute temperature and relative temperature between sink and system, and is often graphed or averaged against expected conditions . </P> <P> The equation is: </P>

The coefficient of performance (cop) of a refrigerator is defined as the ratio of