The first modern electrical air conditioning unit was invented in 1902 and its purpose was to improve conditions in a printing plant. Not only could it cool the air, it could also control humidity. According to WikiPedia (//en.wikipedia.org/wiki/Air_conditioning), the air conditioning unit was invented by Willis Carrier in Buffalo New York.
After a period of time, air conditioning started to be used to improve comfort in houses and by the 1950s retail sales dramatically kicked off.
The origination of air conditioning is thought to come from ancient Egypt. The ancient Egyptians would hang reeds moistened with water in the windows for the air to blow through. The evaporating water from the reeds would cool the air blowing in through the window and it would also make the air more humid. More humidity in a dry hot desert was a welcoming thing.
In his book, “Karl, The Universe and Everything”, Dr Karl Kruszelnicki writes and explains that Standard 55 “is a set of guidelines on how to regulate indoor temperature and humidity”.
Dr Karl continues to explain that the standards were introduced in 1966 and took into account six factors, including four environmental and two human based. The four environmental factors are outside air temperature, amount of heat energy that is radiating from various surfaces, air humidity, and air speed.
The two human factors are Metabolic Equivalent of Task (MET) and clothing.
In modern times, nearly everyone in developed countries uses air conditioners and they are another modern convenience taken for granted and consequently the world would come to an end if they were taken away from us.
Air conditioners currently come in many different forms and types. There are systems for all types of applications. The most popular system in Australia in these times is the split system reverse cycle air conditioner. This incredibly useful unit is not only capable of cooling an averaged size house down but in winter is extremely capable of heating the house up.
The biggest problem with air conditioners is that they consume a fair amount of electricity. In the modern times of high electricity prices this poses a problem for lower income households, however engineers are continuously working on improving the efficiency of air conditioners.