In everyday life, split systems are usually called air conditioners, although this name does not fully reflect the principle of their operation. Meanwhile, the arrangement of air conditioning systems is quite interesting.
The principle of operation of the split system is based on the sorption and movement of low-grade heat from one climatic zone to another, using additionally applied energy for this. The second law of thermodynamics says that the transfer of thermal energy is possible only from a more heated body to a less heated one. When split systems work, this rule is violated by introducing an intermediary into the system. The split-system device is quite simple, and the system itself includes two free-standing units.
Indoor unit (cooler)
The indoor unit of the air conditioner is installed in a refrigerated room and is an element of a split system with the most simple device. It houses an electronic control unit, a thermostat, a turbofan and a radiator with capillary tubes. The main task of the indoor unit is to cool the warm air in the room, driving it through the radiator, and to control the operation of all split-system devices through the network of electrical cables. The indoor unit is connected to the outdoor unit by means of two copper pipes and an electric cable that supplies the outdoor unit with mains voltage. In more advanced split systems, there is a control signal cable. Also in the connecting line there is a flexible tube for removing condensed moisture.
Outdoor unit (evaporator-condenser)
The outdoor unit has a double function. Firstly, it houses all the large and noise-generating system elements. This makes the operation of the air conditioner almost inaudible for the inhabitants of the refrigerated room. The second task of the outdoor unit is to carry out a whole chain of transformations to transfer heat from one room to another. For this, a compressor, an evaporator, a capillary radiator and a vane fan are installed in it.
The principle of interconnected work
The work of a split system consists in transferring a special refrigerant gas through a closed system of copper pipes, which has a low boiling point and changes its state of aggregation several times, alternately absorbing and then releasing heat. The cold gas, passing through the capillary radiator of the indoor unit under the action of the turbofan, heats up from the air, while the latter, respectively, is cooled. The heated gas flows through a connecting pipe to an external unit, where it is compressed by a compressor to a liquid state. When compressed, a significant amount of heat is released from the gas, which is released into the external environment during the passage of the liquefied gas through the radiator of the outdoor unit, blown by a blade fan. The cooled gas, which has a low boiling point, enters the evaporator. There it loses pressure and becomes even cooler, after which it is transported through the connecting pipe to the indoor unit.
