Typically, air conditioners don’t require recharge because it’s a sealed system. A recharge is indicative of a system leak. The leak can be minor or major, resulting in complete loss of charge. If the system has the old refrigerant R-22 and you have a leak, the system will require replacement because R-22 is no longer available and prohibited. Refrigerant (R-22 or R410A) is typically added in pounds with a scale. If anyone is saying they added refrigerant for a recharge, be sure to ask for a picture of the scale weigh-in weight to show that it’s accurate because refrigerant is expensive.