Air conditioning systems use heat pump technology to provide heating, cooling and hot water where required. Most heat pumps require only a small amount of electricity to harvest, upgrade and move heat from one location to another.
To achieve this a vapour compression cycle is used, which has the ability to move heat from one space to another. Low temperature heat from the environment can be increased to usable temperatures inside the building in the winter, or waste heat from a building can be moved outside in the summer, or even recovered in to hot water.
The efficiency of a heat pump is known as the Coefficient of Performance or CoP (or Energy Efficiency Ratio (EER) in cooling mode). This is a ratio of the heat delivered to power consumed.
The operation of a heat pump is similar to a refrigerator. This process is known as the vapour compression cycle and the following is a more detailed explanation and example of the system delivering heat into a building. Cooling is the same, but the heat is taken from the inside and rejected to the outside.