How do you calculate a COP?

In its simplest form this relates to HEATING OUTPUT divided by the POWER INPUT E.g. with a COP of say 4 to 1 the HEATING OUTPUT relates to 4 Kw and the POWER INPUT 1 KW.

Note: Remember that COPs are instantaneous measurements of performance and are usually quoted by manufacturers to an international standard. COPs will vary according to the air or water entering the heat pump and with the temperature of the air or water being treated by the heat pump.