How do they work?
Your residential home or commercial business air conditioner is moving heat from the inside to the outside, resulting in a cooler indoor environment. The air is cooled by blowing across an evaporator coil. This works just like the cooling that happens when water evaporates from your skin.
The evaporator coil is filled with a special liquid called freon refrigerant, which changes from a liquid to a gas as it absorbs heat from the air. The freon refrigerant is pumped outside the house or business to the outside condenser coil where it gives up its heat and changes back into a liquid. This outside coil is called the condenser because the freon refrigerant is condensing from a gas back to a fluid just like moisture on a cold window.
A freon pump, called a compressor, is used to move freon refrigerant between the evaporator coil and condenser coil through copper refrigerant lines. This changes the pressure of the refrigerant so that all refrigerant evaporates or condenses in the appropriate coils. The more efficient your new HVAC is, the lower your electric bills will be. The energy to do all of this is provided by the motor that runs the compressor. The entire system will normally provide about three times the cooling energy that the compressor uses. This happens because the changing of refrigerant from a liquid to a gas and back again lets the system move much more energy than the compressor uses.