Air conditioning (often referred to as aircon, AC or A/C) is the process of altering the properties of air (primarily temperature and humidity) to more favourable conditions, typically with the aim of distributing the conditioned air to an occupied space to improve comfort. In the most general sense, air conditioning can refer to any form of technology, heating, cooling, de-humidification, humidification, cleaning, ventilation, or air movement, that modifies the condition of air.
In common use, an air conditioner is a device (most commonly a home appliance or automobile system) that lowers the air temperature. The cooling is typically done using a simple refrigeration cycle, but sometimes evaporation is used, commonly for comfort cooling in buildings and motor vehicles. In construction, a complete system of heating, ventilation and air conditioning is referred to as “HVAC”.
Air conditioning can also be provided by a simple process called free cooling which uses pumps to circulate a coolant (typically water or a glycol mix) from a cold source, which in turn acts as a heat sink for the energy that is removed from the cooled space. Free cooling systems can have very high efficiencies, and are sometimes combined with seasonal thermal energy storage (STES) so the cold of winter can be used for summer air conditioning. Common storage media are deep aquifers or a natural underground rock mass accessed via a cluster of small-diameter, heat exchanger equipped boreholes. Some systems with small storage are hybrids, using free cooling early in the cooling season, and later employing a heat pump to chill the circulation coming from the storage. The heat pump is added-in because the temperature of the storage gradually increase during the cooling season, thereby declining in effectiveness. Free cooling and hybrid systems are mature technology.
Air conditioners are vital to any building and may serve the following purposes
- Helps in preserving the heath, comfort and convenience of the occupants of the building or structure
- Helps in improving the quality of certain industrial products like artificial silk, cotton cloth, etc.
- It provides comfortable working condition resulting in an increase in the production output of the workers.
- In case of air conditioning in travelling such as air conditioned railway coaches, cars, airlines, etc. help in the easing the arduous travels and help in making the journey more comfortable.
- It helps in the process of marketing. Air conditioning is an essential facility that is imperative for any shop, arcade, restaurants, banks, theatres, etc.
- It may also be used for maintaining the optimum environment for the storage of chemical and compounds such as in laboratories, construction sites, etc.