What is COP?COP, or Coefficient of Performance, is the ratio of cooling (or heating) to energy consumption. For example, a refrigerator with a COP of 2 moves 2 watts of heat for every watt of electricity consumed. An air conditioner with a COP of 4 moves 4 watts of heat for every watt consumed.
For domestic heating, COP is also used. An electric heater has a COP of 1: each watt of power consumed produces 1 watt of heat. Conventional heat pumps have COPs of 2-5, delivering 2 to 5 times more energy than they consume.
What is Carnot Efficiency?Carnot Efficiency can also be called "Maximum Possible COP". It describes the theoretical limits. If we had a *perfect* heat pump, it would have a Carnot efficiency of 100%.
The Carnot cycle can be thought of as the most efficient cooling cycle allowed by physical laws. When the second law of thermodynamics states that not all the energy supplied to a cooler can be used to cool, the Carnot efficiency sets the limiting value on the fraction of the energy which can be so used.
For comparison purposes, a typical thermoelectric (Peltier) cooler has a Carnot efficiency of about 5-8%. A typical domestic refrigerator compressor has a maximum Carnot efficiency of about 45%. Cool Chips are projected to achieve 55% of Carnot.
In a cooling applications, there is a maximum amount of cooling which can occur with a given amount of electricity. This amount is the maximum Carnot efficiency. It means that the colder one wants to make something, the more energy it requires.
Copyright © 1995 - 2012 Cool Chips plc. All rights reserved.
Forward Looking Statement may be found at http://www.coolchips.gi/fwdlook.shtml.