The first modern air conditioning system was developed in 1902 by a young electrical engineer named Willis Haviland Carrier. The system was designed to remove humidity in the plant building of a publishing company in Brooklyn, NY. Cool air holds less moisture than warm air. The air cooled as it passed across the cold pipes which reduced the humidity in the building. Reducing the humidity in the air also has the side benefit of lowering the air temperature. For more detailed working principle please check how air conditioning systems work.
Air conditioners are very similar to refrigerators. Refrigerator moves heat from the inside of refrigerator to outside of refrigerator. The temperature of inside of refrigerator is lowered. Similarly, air conditioner system moves the heat of inside of a building via refrigerant to outside of the building and release the heat into atmosphere through condenser unit.
To better understand the basic knowledge of air conditioner system, a video clip from Youtube is pasted here.
Frequently Asked Questions
Most manufacturers identify which refrigerant your AC unit uses on a large sticker or nameplate located either on its compressor or condenser unit. It may read “R-410A” or “R22”. If your AC unit is retrofit from R22, the HVACR technician may mark it as “R407C” , “R422D” , etc.
Check the nameplate on the outside condenser unit. At the refrigerant line you will see the type of refrigerant and the amount of refrigerant used: xx lb xx oz (xx kg).
Find the model number on the nameplate of the outside condenser unit. Within the string of letters and numerals, you should find an even, two digit number. The possible numbers are: 12, 18, 24, 30, 36, 42, 48, 54, 60, etc. Divide the number by 12 to get your AC unit’s tonnage. The tonnages of above numbers are: 1, 1.5, 2, 2.5, 3, 3.5, 4, 4.5, 5, etc.
In US market, in addition to the central forced air conditioner system, there are four other popular AC systems: Ductless mini split system and window air conditioner, package system, and hotel package terminal air conditioner (PTAC) system.
Four other systems are listed blow. Please click on the system you are interested to understand the basic principle of the AC system.