How do an 1.5hp air conditioner works?

All refrigerant based air conditioners use a principle called "Heat of vaporization", in which liquids absorb heat when they change state to a vapor.

1. Refrigerant gas is compressed, using the 1.5 hp compressor. When the refrigerant is compressed it becomes hot, so the heated refrigerant is passed through a cooling coil and outside air is blown across the coil to cool the refrigerant to outside temperature.
2. When temperature of the compressed refrigerant drops below a threshold, it changes state to a liquid.
3. The liquid refrigerant is allowed to pass through an "expansion valve". The valve maintains a relatively high temperature on the "compressed" side, then the gas quickly drops to a low pressure.
4. Using "Boyle's Law", we know that as a gas expands, the temperature will drop.
5. The expanded refrigerant cools rapidly and is passed through another coil, which cools the inside air as the air warms the refrigerant.
6. The gas is then compressed again, as described in step 1.