Where does freon go in a mini split?

Refrigerant (commonly referred to as Freon) in a ductless mini-split system circulates exclusively inside a closed, hermetically sealed loop composed of copper tubing lines, the outdoor condenser coil, and the indoor evaporator coil. The refrigerant undergoes continuous phase changes, absorbing heat from your indoor space when liquid turns to gas in the evaporator, and releasing that heat outdoors when compressed back into liquid by the inverter compressor. Because the system is a closed loop, refrigerant is never consumed or vented during normal operation; it remains contained entirely within the copper lines and coils unless a physical breach or loose flare connection allows gas to escape into the atmosphere. You can troubleshoot by inspecting lines for oil leaks. You can verify system integrity when pressure gauge testing confirms the full factory refrigerant charge is retained.