For thousands of years, people have been doing whatever they can to control the temperature of their surroundings. For instance, in the 3rd century, Roman Emperor Elagabalus dispatched 1,000 slaves to the mountains to fetch snow for his gardens. Thousands of years later the first window unit air conditioner was introduced, in 1932. Unfortunately, however, it was decades before the average person could afford air conditioners with an air conditioning coil.
Air conditioning was actually used a lot by movie theaters during the Great Depression, as despite its high cost it was a huge draw for patrons who wanted to get out of the heat. Years later, movie theaters still use air conditioners quite regularly.
Cleaning air conditioner coils can actually be difficult, as air conditioner evaporator coils build up dirt, mold and debris which can result in decreased performance and increased energy uses, which saps your money and gives you nothing to show for it.
People can also get HVAC units in their house. HVAC stands for heating, ventilation and air conditioning, and the main purposes of their systems are to help maintain good indoor air quality through adequate ventilation, as well as providing thermal comfort. However, fixing air conditioners can be difficult. On that note, HVAC air filters can be replaced, which makes HVAC cleaning a whole lot easier than specific air conditioning coil cleaning.