COP is an acronym for Coefficient Of Performance. It is a term used to rate the efficiency of a HEAT PUMP at any one given set of conditions. See HSPF for another heat pump rating term. Heat Pumps use electricity to move heat energy from one space to another.
The simplest way to heat with electricity as an energy source is what we call STRAIGHT RESISTANT ELECTRIC HEAT. This method, while the least expensive to buy, is also the most expensive to operate. It has a COP of 1. Quite simply, this means that for every dollar's worth of electricity you buy, you get one dollar's worth of heat. Not bad, you might say, "that's 100% efficient", but what if you could get 500%?
Since HEAT PUMPS don't actually burn up the electricity you buy, they can get you more heat than you pay for.
An AIR TO AIR HEAT PUMP can easily average a COP of over 3, which means you get $3.00 worth of heat for every $1.00 worth of electricity you buy. The COP on ATAHPs vary widely from near 4 on warm days to below 2 on very cold days. This is where DUAL FUEL systems really shine.
A GEOTHERMAL HEAT PUMP can easily reach a COP of nearly 5, which means you get $5.00 worth of heat for every $1.00 worth of electricity you buy. Geothermal COPs do not vary much from one day to the next.
The higher the number, the lower your utility bills are. Please take time to read about AIR TO AIR HEAT PUMPs a GEOTHERMAL HEAT PUMPs. & DUAL FUEL SYSTEMS
Weber Refrigeration Heating and Air Conditioning