Air conditioners work by transferring heat energy from inside the home to the exterior. Liquid refrigerant absorbs heat from the home, becomes a gas, and travels to the outside. A compressor and condenser then converts it back to a liquid, and it releases the energy, thus beginning the cycle again.
When the refrigerant arrives at the compressor, it is a cool, low-pressure gas. The compressor is a pump that increases the pressure on the fluid, packing molecules closer together. Packing the molecules increases their energy and temperature. The high-pressure gas leaves the compressor to enter the condenser, a coiled tube surrounded by fins, where heat dissipates. The process of compressing the gas and dissipating heat converts the refrigerant into a high-pressure liquid. The liquid moves through a tube to the evaporator. As the liquid passes through the orifice into the evaporator, it enters the low-pressure side of the air conditioner and converts to a gas. This evaporation process absorbs heat, as the molecules spread apart.
Inside the evaporator unit, a blower circulates air from the home through the evaporator coils. As this air gives up heat to convert the refrigerant to a gas, it cools. This cooled air travels through ducts to reduce the temperature inside the home. As the air passes through the evaporator coils, water condenses on the cold surfaces, lowering the humidity inside the home for additional comfort.