Aire Acondicionado

Air conditioning
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For the appliance, see Air conditioner.
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.[1] An air conditioner (oftenreferred to as AC or air con) is an appliance, system, or machine designed to change 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 but sometimes using evaporation, commonly for comfort cooling in buildings and motor vehicles.
Contents[hide] * 1 History * 1.1Pre-industrial cooling * 1.2 Mechanical cooling * 1.3 Electromechanical cooling * 1.4 Refrigerant development * 2 Air-conditioning applications * 3 Humidity control * 4 Energy use * 5 Health issues * 6 Refrigerant environmental issues * 7 Portable air conditioners * 8 Heat pumps * 9 See also * 10 References |
[edit] History
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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 down. Other techniques in medieval Persia involved the use of cisternsand 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 electrical air conditioning was invented and used in 1911 by Willis Haviland Carrier.
[edit] Pre-industrial cooling
The 2nd-century Chinese inventor Ding Huan (fl. 180) of the Han Dynasty invented a rotary fan for air conditioning,with seven wheels 3 m (9.8 ft) in diameter and manually powered.[2] In 747, Emperor Xuanzong (r. 712–762) of the Tang Dynasty (618–907) had the Cool Hall (Liang Tian) built in the imperial palace, which the Tang Yulin describes as having water-powered fan wheels for air conditioning as well as rising jet streams of water from fountains.[3] During the subsequent Song Dynasty (960–1279), writtensources mentioned the air-conditioning rotary fan as even more widely used.[4]
In the 17th century, Cornelis Drebbel demonstrated "turning Summer into Winter" for James I of England by adding salt to water.[5]
In 1758, Benjamin Franklin and John Hadley, a chemistry professor at Cambridge University, conducted an experiment to explore the principle of evaporation as a means to rapidly cool an object.Franklin and Hadley confirmed that evaporation of highly volatile liquids such as alcohol and ether could be used to drive down the temperature of an object past the freezing point of water. They conducted their experiment with the bulb of a mercury thermometer as their object and with a bellows used to "quicken" the evaporation; they lowered the temperature of the thermometer bulb down to −14 °C(7 °F) while the ambient temperature was 18 °C (64 °F). Franklin noted that, soon after they passed the freezing point of water 0 °C (32 °F), a thin film of ice formed on the surface of the thermometer's bulb and that the ice mass was about a quarter-inch thick when they stopped the experiment upon reaching −14 °C (7 °F). Franklin concluded, "From this experiment, one may see the possibility offreezing, a man to death on a warm summer's day".[6]
[edit] Mechanical cooling

Three-quarters scale model of Gorrie's ice machine. John Gorrie State Museum, Florida.
In 1820, British scientist and inventor Michael Faraday discovered that compressing and liquefying ammonia could chill air when the liquefied ammonia was allowed to evaporate. In 1842, Florida physician John Gorrie used...