You probably know that something called refrigerant (also referred to as Freon, which is a specific brand of refrigerant) is an essential component for your air conditioner to do its job. But do you know how it works? It’s not actually a type of fuel, like gasoline in a car, which is consumed in order to create the energy to run a system. Refrigerant instead circulates without being consumed. But refrigerant is not like oil in a car either, which circulates but eventually degrades over time and needs to be replaced.
To answer the question in the title, refrigerant should remain at the same level for your AC’s service life and never need to be replaced or have more put in. If you hear a supposed AC “expert” tell you that your system’s refrigerant needs to be regularly topped off, don’t believe them. The factory set charge of refrigerant in your AC is exactly what it should be.