Mr D. Tail is enjoying his brand new air conditioning system while reading today’s newspaper. 

How the air conditioning system works: 
The indoor unit, the split air conditioner, converts warm indoor air to chill indoor air, during this phase the liquid is converted to a gas that absorbs heat. The outdoor unit, the condenser unit, is rejecting the unwanted heat to outside, during this phase the gas cools, it changes back to a liquid, and the process starts again.