Don’t get fooled by companies selling pre-charged air conditioners. Over the past few years I have received many questions about purchasing pre-charged mini split air conditioners. There are some companies that advertise that their compressors within the condenser are pre-charged with refrigerant. This is a true statement. Every manufacturer I know installs compressors that are pre-charged with refrigerant. This does not mean that you can hook up a copper line set and the equipment will operate properly. Pre-charged compressors usually have approximately 13 to 16 feet of refrigerant. No matter what length line set you use, the refrigerant amount will have to be regulated and charged to ensure proper pressure settings. A professional HVAC installer will have to hook up gauges and increase or reduce refrigerant for proper operation. If refrigerant pressures are not within recommended levels, problems will ensue. Also, before a refrigerant line set is charged, it will need to be vacuumed of any contamination that may have entered. This is also done by a professional HVAC installer. Finally, remember that warranties are void if mini split air conditioners are not charged by a HVAC professional. To date there is only one system that is pre-charged with refrigerant and can be connected without the use of a HVAC professional, AmericAire’s DIY system.
The AmericAire ACEDIY12HP110/ACCDIY12HP110 has a pre-charged compressor and line set that is already connected to the indoor evaporator. The system is vacuumed and charged at the warehouse and built with special quick-lock connecting fittings. This fitting locks into place at the outdoor condenser and charges the entire unit for 25 feet of stainless steel line set. The special stainless steel line set is made special to help prevent leaks that can occur with copper lines. If you need to have a line set longer than 25 feet, the AmericAire DIY system is not recommended. It is a great system and you can check out its specifications at this link.