LG HVAC A duct-free system, also known as a “split” air conditioner system, is made up of or includes two units: an indoor unit to deliver conditioned air to the room, and an outdoor unit to remove heat collected from the space. The compact refrigerant lines run between the two units. The system eliminates the need for ductwork. Duct-free systems are ideal for older homes that have no ductwork, room additions, or areas in homes that just never seem to be the right temperature or are never comfortable. LG duct-free systems are available in a range of sizes and styles--including systems that can heat and cool multiple rooms with a single outdoor unit to fit almost any need. The indoor units are available in many different types to fit with the look and feel of your home.