The History of Air-Conditioning
The term air conditioning refers any form of cooling, dehumidification, heating, ventilation or disinfection that modifies the condition of air. The term “air conditioner” (AC, A-C, A/C) is a generic term for an appliance or system designed to regulate the air temperature and humidity within an area. Most modern air conditioning systems are combined with a heating system and are used for cooling as well as heating depending on the air properties at a given time. These units are often referred to as “whole house units”, “central units”, or “HVAC systems”.
Although the true origins of the concept of air conditioning is unknown, examples of man attempting climate control can be traced back as far as ancient Rome. The home of certain wealthy Romans had aqueduct water circulate through the walls to cool them. Mediaeval Persians and Chinese also designed methods to cool their habitations: the Chinese utilized large rotary fans while the Persians used cisterns and wind towers to cool buildings during the hot season. These cisterns-large open pools in a central courtyards collected rain water while wind towers had windows that could catch wind and internal vanes to direct the airflow down into a building over the cistern and out through a downwind cooling tower. The cistern water would evaporate, thereby cooling the air in the building.
Modern air-conditioning can trace its roots to 1902, when Willis Haviland Carrier invented a device to improve the manufacturing process control in a printing plant. His invention not only controlled the temperature, but also the humidity to help maintain consistent paper dimensions and ink alignment. Carrier's “Apparatus for Treating Air” was initially sold to industrial and manufacturing buildings and a few hospitals due to the fact that the units were large, expensive, and dangerous due to the ammonia that was used as coolant.
In 1922, Carrier replaced the ammonia with the non-toxic coolant dielene and added a central compressor to reduce the size of the unit. This led to A/C units being installed in areas such as movie theaters office buildings, and department stores. Air conditioning largely remained for commercial and industrial use until after World War II, when technological advances and a bolstered economy made it possible for more people to have an a-c unit in their homes.