An air conditioning system is manufactured to use a specific amount of chemical refrigerant. This is known as an air conditioner’s charge. People often make the mistake of thinking refrigerant is an energy source for an air conditioner. It isn’t. The energy source of an air conditioner is electricity. Refrigerant is the heat transference medium that allows the air conditioner to move thermal energy outside of the house (cooling the indoor air) and exhausting it. The refrigerant evaporates and condenses in a cycle and never dissipates—so it will never get “used up.”
That doesn’t mean it can’t have a low charge, however! An amateur may have put the wrong charge in the AC when it was installed. The refrigerant lines can also corrode and develop leaks. Whatever the cause of an undercharged air conditioner, it means a range of problems and eventually a broken down AC.
The best way to ensure a great AC installation is to work with licensed HVAC professionals. In fact, this is the only way to do it—unless you are an HVAC professional yourself. Trying to take on the installation job on your own or allowing an amateur to do it is a big “nope.”