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How Air Conditioning works

Air-conditioning is the removal of heat from indoor air for thermal comfort

In another sense, the term can refer to any form of cooling, heating, ventilation, or disinfection that modifies the condition of air. An air-conditioner (often referred to as A/C or air-con.) is an appliance, system, or machine designed to stabilise the air temperature and humidity within an area (used for cooling as well as heating, depending on the air properties at a given time), typically using a refrigeration cycle, commonly for comfort cooling in buildings and motor vehicles.

The concept of air-conditioning is known to have been applied in Ancient Rome, where aqueduct water was circulated through the walls of certain houses to cool them. Similar techniques in medieval Persia involved the use of cisterns and wind-towers to cool buildings during the hot season.

Modern air-conditioning emerged from advances in chemistry during the 19th century, and the first large-scale electrically-powered air conditioning system was invented and used in Brooklyn, New York during 1902 by Willis H. Carrier.


Air-conditioning Basics

Diagram of a typical air conditioner.Domestic air-conditioners do not lower the temperature in homes by pumping cool air in. What happens is that the warm air from your house is drawn in to the unit and cycled back out as cooler air. This cycle continues until your thermostat reaches the desired temperature. An air-conditioner is basically a refrigeration system without the insulated box. It uses the evaporation of a refrigerant to provide cooling.

How the evaporation cycle in an air-conditioner works:

The compressor compresses cool refrigerant gas, causing it to become hot, high-pressure refrigerant gas (red, in the diagram above).

  1. This hot gas runs through a set of coils so it can dissipate its heat, and it condenses into a liquid.
  2. The liquid refrigerant runs through an expansion valve, and in the process it evaporates to become a cold, low-pressure gas (light blue in the diagram above).
  3. This cold gas runs through a set of coils that allow the gas to absorb heat and cool down the air inside the building.

Mixed in with the refrigerant is a small amount of lightweight oil. This oil lubricates the compressor.

Coolheat engineers are fully-trained and understand the principles of refrigeration.


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