An air conditioner typically uses a centrifugal compressor to drive a fluid called refrigerant through a series of chambers. A centrifugal compressor is like a fan with many blades spinning at a high rate of speed. This quick spinning forces the refrigerant to the outside of the blades, where it is pressurized and shot out the other end into the condenser.
The Condenser Coil
The compressor needs to create a lot of force because the condenser is a pressurized coil. The refrigerant is compressed and packed tightly into it. When a fluid is compressed, it heats up. As the refrigerant flows through the condenser coil, the heat leaks out into the air, cooling the fluid down.
The refrigerant then flows through a small nozzle into the evaporator coil. The evaporator is a low pressure coil. When the refrigerant is depressurized it cools down quickly, just as it heated up when it was pressurized. This cool liquid then flows through the evaporator. A fan blows on the evaporator, cooling air and blowing it out of the air conditioner. This gradually warms up the refrigerant. After it has flown through the evaporator, the refrigerant is pulled back into the compressor to start the whole process again.