An air conditioner (often referred to as AC) is a major or home appliance, system, or mechanism designed to change the air temperature and humidity within an area (used for cooling and sometimes heating depending on the air properties at a given time). 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".
The basic concept behind air conditioning is known to have been applied in ancient Egypt where reeds hung in windows had water trickling down. The evaporation of water cooled the air blowing through the window, though this process also made the air more humid. In Ancient Rome, water from aqueducts was circulated through the walls of certain houses to cool them down. Other 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 electrical air conditioning was invented and used in 1911 by Willis Haviland Carrier. The introduction of residential air conditioning in the 1920s helped start the great migration to the Sunbelt.
Famous quotes containing the words air and/or conditioning:
“The curfew tolls the knell of parting day,
The lowing herd wind slowly oer the lea,
The ploughman homeward plods his weary way,
And leaves the world to darkness and to me.
Now fades the glimmering landscape on the sight,
And all the air a solemn stillness holds,
Save where the beetle wheels his droning flight,
And drowsy tinklings lull the distant folds.”
—Thomas Gray (17161771)
“The climacteric marks the end of apologizing. The chrysalis of conditioning has once for all to break and the female woman finally to emerge.”
—Germaine Greer (b. 1939)