How an Air conditioner works

How an Air Conditioner works.

basic diagram of an AC

We never thought how we get cool breeze? What mechanism is actually involved in producing cold air in burning hot summers? Here is a simple diagrammatic explanation of working principle of an air conditioner. No matter what type of air conditioner you are using, windowed, split wall mounted, cabinet floor standing or roof top type, basic principle is same inside them. Even inverter air conditioner has some modifications to primitive design but it still follows the same principle and laws of thermodynamics.

Explanation: 

 Every air conditioner has a compressor inside it. It works to compress and pump the refrigerant gas. Compression of refrigerant generates heat. To dissipate this heat, compressed refrigerant is pumped to condenser coils where a fan blows the heat out to outer atmosphere. During the process, refrigerant takes the liquid form. This liquid refrigerant is pumped toward expansion valve.

Expansion valve has temperature sensor attached to it which works in correlation with thermostat settings. Expansion valve releases the appropriate amount refrigerant to evaporator (cooling coils) where liquefied refrigerant takes gaseous form. Conversion from liquid to gaseous state due to expansion produces chillness because energy is absorbed from the surrounding. Air when passes through fins (attached to coils) get cooled and blown to room. The refrigerant in cooling coils then enters the compressor and gets compressed once again. The cycle continues until the compressor is not shut down.In a nutshell, air conditioner draws heat from the indoor and releases it to the outdoor. Indoor acts as a source and outdoor as a sink for heat.

 Inverter air conditioners: 

 These air conditioners use an inverter to control the speed of compressor. Electricity is first rectified to DC (direct current) and then inverted back to required frequency AC (alternating current) using pulse width modulation. Thus compressor speed can increase and decrease according to the room temperature. Such air conditioners are extremely energy efficient and consume approximately 30-50 % less electricity than old fashioned air conditioners. If a 1 ton non-inverter air conditioner consumes constant 1600 Watts of electricity, inverter type air conditioner consumes less than variable 800-1100 Watts depending upon temperature of room. Such air conditioners are expensive due to additional machinery inside them but cost is slowly recovered in electricity bills. Their other benefits include quiet operation, faster cooling, no indoor temperature fluctuations and no voltage peaks caused by compressor.

Air conditioner as a heater:   

When air conditioner is used as a heater, the process which is shown and explained above just simply gets reversed. As a result of reverse mechanism, hot air is propelled towards indoor and cool air towards outdoor.