An air conditioner makes your home cooler, true. But in terms of how the system actually works, it's more accurate to say that an air conditioner makes your home less warm. What it's really doing is drawing heat energy out of the house and transferring that heat to the outdoors (where it's already so blasted hot that nobody notices the difference).

 

	A cool gas (the refrigerant) flows into the compressor, where it is compressed into high temperature, high pressure gas. The compressor pumps this hot gas through the tubes to . .
	The condenser coil in the outdoor unit (also called the condenser.) As the hot gas passes through the condenser coil tubes, heat is transferred from the gas, through the metal fins surrounding the air. This causes the gas to cool and condense into liquid. A motorized fan forces air across the condenser metal fins to increase the rate at which heat is transferred. Meanwhile...
	The liquid refrigerant flows through tubes to the evaporator inside your home. Once inside the evaporator, the refrigerant goes through a pressure reducing device that causes the refrigerant to quickly expand and to cool rapidly. Then the cold refrigerant travels through the tubes of the evaporator coil where it absorbs heat energy from the surrounding air and turns back into a gas (it evaporates). Also, humidity from warm moist indoor air condenses on the evaporator and drains away. Meanwhile...
	A blower draws warm air from the house, moves it through the evaporator where heat energy is removed and blows this air on through the ductwork into your home -- cooler, dryer and altogether more pleasant. From there...
	The cooler gaseous refrigerant travels through tubes back to the compressor where the cycle begins again.

So you see, that air blowing out the top of your outdoor unit is so hot because it contains heat energy that was inside your house just a couple of minutes before.