Air conditioning, commonly referred to as “air con” in mainland China and “AC” in other regions, is achieved through an electrical appliance, system, or mechanism that uses a refrigeration cycle to remove heat from the air. In architecture, a complete heating, ventilation, and air conditioning system is known as HVAC (Heating, Ventilation, Air Conditioning, and Cooling).

Air conditioning systems are most common and widespread in East Asian countries, including Japan, South Korea, major cities in mainland China, Hong Kong, and Taiwan. Due to hot summer weather and high standards of living, air conditioning has become a necessity. Most air conditioning systems manufactured in Japan and neighboring regions are window-type or split-type, with split-type systems being more advanced and expensive. As living standards rise, air conditioning is also gradually becoming widespread in tropical regions of Southeast Asia, such as Malaysia, Singapore, and the Philippines.

In the United States, residential air conditioning systems are more common on the East Coast and in the South, with penetration rates in some areas rivaling those in East Asia. Central air conditioning systems are relatively common in the U.S. and have become the de facto standard in new residential construction in Florida.

In Europe, residential air conditioning systems are relatively rare, partly due to the region’s milder climate and social factors; however, global warming may lead to greater adoption of air conditioning systems.

Although one of the purposes of air conditioning is to purify the air—for example, by incorporating air filters to prevent allergens from entering an enclosed environment and thus avoid allergic reactions—air conditioning is believed to trigger asthma (vasomotor asthma or vasomotor rhinitis), a reaction typically caused by changes in air pressure or temperature.

By Michael Chiu, MWS, CI
Previously published in Ming Pao Daily News