Air conditioning is a term referring to any process or system that controls the temperature, humidity, cleanliness, and movement of indoor air. When the weather is hot, it cools the air. When the weather is cold, it warms the air. It also adds or removes moisture to and from the air as needed. By controlling air movement, air conditioning is able to remove dust and dirt by bringing fresh air into a space and pushing stale air out. An air conditioning system is any mechanism designed to stabilize and control the condition of the air in a given space, most commonly in buildings, cars, and other forms of public and private transportation.
The first known form of air conditioning is said to have been developed in Ancient Rome. Aqueduct water was circulated within the walls of luxurious Roman estates to keep them cool.
A different system was used in medieval Persia, involving the use of pools and fans. Cisterns, or large man-made pools, were placed in central locations such as courtyards to catch rain water. As the water evaporated, it cooled the air around it. Wind towers were then used to blow the cool air and circulate it throughout the surrounding buildings. The first ventilators were supposedly invented in medieval Egypt, with some historians claiming that at one time nearly every home in Cairo had one.
The type of air conditioning system found in most homes today is derived from a model invented in 1902 by a man named Willis H. Carrier. A research engineer, Carrier developed the system as a means of regulating the temperature and humidity in a printing plant in order to provide the best possible atmosphere in which to process paper and ink.
The idea soon caught on elsewhere, finding profitable use in the private sector as well as the world of industry. In 1906, a textile engineer named Stuart W. Cramer used the term "air conditioning" for the first time. It wasn't long before Carrier applied the term to his own invention. Thus, the first modern air conditioning system was born. Or at least christened.
Every air conditioning system is designed to perform in one of two capacities: comfort or industry. Those designed for comfort can be found in homes, restaurants, cars, airplanes, trains, ships, buses, and hospitals. It is also worthy of mention that pleasurable temperatures are not the only comfort these systems offer. They can relieve the discomfort of allergies by removing pollen from the air, make long commutes less taxing on drivers and passengers alike, and even help to preserve the health of patients in hospitals.
In business and industry, air conditioning systems can improve the efficiency of workers, ensure uniformity in metal work, prevent too much or too little moisture from damaging fragile paper products during manufacture, and keep food fresh during longs periods of shipment and storage.