Working Principles of Air Conditioning

The compressor, condenser, throttle (the capillary tube, thermostatic device) and evaporator are connected by thin-walled copper pipes (recently aluminum) and form a cooling circuit, inside which the coolant circulates (traditionally they use the mixture of Freon with a small quantity of compressor oil in the air conditioner, but in accordance with the international agreements the production and use of old varieties that deplete the ozone layer, is being phased out, they mostly use Freon R-407 and R-410A in modern air conditioners are).

When air conditioning process is the following (by the example of Freon R22): the gaseous coolant at a low pressure of 3-5 atmospheres and a temperature of 10-20 ° C enters the compressor input from the evaporator. The compressor of the air conditioner heats the gas up to a pressure of 15-25 atmospheres and temperature 70-90 ° C following which the freon enters the condenser.

Thanks to the intensive blowing, the freon gives away heat and the air passing through the condenser increases temperature. At the condenser's exit, the freon is already liquefied and with temperature 10 - 20 degrees Celsius more than the air. The warm freon from the condenser enters the regulating valve (in air-conditioners that is a capillary - a thin copper spiral wounded pipe), where the temperature and pressure are lower and the freon begins to evaporate.

After the regulating valve the freon enters the evaporator and continues to turn into vapor until its full transformation back to its gas state and in the process consumes heat. The gas freon with low temperature then enters the compressor and the cycle is repeated. This principle lies in the working process of every air-conditioner, thermopump, refrigerator and it is known as the "reverse Carnot cycle".

The air conditioner (cooler) work is basically impossible without withdrawal the heat from the condenser (or hot junction of the Peltier element). This is a fundamental limitation arising out of the second law of thermodynamics. In common household plants this heat is exhaust, and is discharged into the environment; and its quantity overdraws the value absorbed while cooling rooms (chambers) considerably. At more complex devices the heat is utilized for domestic purposes: hot water and other.