Filling an air conditioning (AC) unit with refrigerant gas is a crucial step to ensure optimal cooling performance. This process involves several careful steps to avoid leaks and ensure the system operates efficiently. First, it’s essential to verify that there are no leaks in the system by performing a thorough inspection. If the system is sealed and leak-free, connect the refrigerant tank to the service port of the AC unit using appropriate gauges and hoses. Before filling, use a vacuum pump to evacuate any air and moisture from the system, ensuring it is completely clean and ready for the refrigerant. Once the system is under vacuum, slowly open the valve on the refrigerant tank to allow the gas to enter the system. Monitor the pressure gauges closely, ensuring the refrigerant is filled to the manufacturer’s specified levels. Overcharging or undercharging can lead to inefficiency or damage to the unit. After filling, check the system again for any leaks and test the AC unit to ensure it is cooling effectively. Proper handling of refrigerants is essential due to their environmental impact, so always follow safety guidelines and dispose of any empty refrigerant containers responsibly.