People often misunderstand the role of refrigerant (a.k.a. “Freon”) in an air conditioner. Refrigerant is not a type of fuel: an AC doesn’t use up its refrigerant as it runs the way that a car uses gasoline or a cell phone drains its electrical charge. Refrigerant remains at the same level in an air conditioner as it moves between liquid and gaseous states, absorbing heating through evaporation and then releasing it through condensation.
However, an AC can lose refrigerant due to leaks… and when this happens it will cause severe problems for the system: