Air Conditioning – A system or process for controlling the temperature, humidity or purity air in a space such as a building


Air conditioning systems work by moving heat from one place to another. In a split system, usually split into 2 units consisting of 1 indoor and 1 outdoor, air is drawn into the indoor unit and passes over an evaporator coil, think of the indoor unit as a big heat absorbing sponge. The heat absorbed then travels to the condenser located in the outdoor unit via copper pipe work and is discharged (or the sponge is wrung out) that’s basically it.


Ok……. A Little More About Air Conditioning 

what is airconThe evaporator coil in the indoor unit is connected to a compressor, condenser and an expansion valve via copper pipe work. Inside the copper pipe work is an environmentally friendly non ozone depleting refrigerant. The refrigerant travels from the condenser through the expansion valve reducing it from a high pressure liquid to a low pressure liquid. The refrigerant then enters the evaporator coil and is changed from a low pressure liquid to a low pressure gas. During this change the temperature of the refrigerant in the evaporator coil is now much colder causing the heat from the drawn in air to be absorbed (like a sponge). The refrigerant is then pumped back to the condenser via the compressor. When the refrigerant is in the compressor it compresses from a low pressure gas to a high pressure gas and when it enters the condenser the heat collected at the evaporator coil is discharged to the outside air (like ringing out the sponge). The refrigerant enters the condenser as a high pressure gas and leaves as a high pressure liquid ready to enter the expansion valve and to carry on another cycle

The above process is used to create a cooling effect in a room, in order to introduce heat the same process and equipment is used but the process is simply reversed and the refrigerant travels in the other direction.

 Principles of Air Conditioning

  • Liquids absorb heat when changed from liquid to gas
  • Gases give off heat when changed from gas to liquid.