What is the definition of a mini split wall unit? A mini split wall unit is an air conditioning system that provides cooling and heating to single rooms or areas. It consists of two parts: an indoor air handler and an outdoor compressor/condenser. The air handler is mounted on an interior wall, usually near the ceiling. The condenser is outside and is connected to the indoor unit with a conduit that houses the power and refrigerant lines. Mini split wall units are great for zoning–you can control the temperature in each room or area for greater efficiency and comfort. They are also typically much quieter than traditional window air conditioners or central air conditioning systems. They can be used to heat or cool spaces up to 400 square feet and cost less to install than central air conditioning systems. In addition, they are energy-efficient, often using less electricity than other options. Mini split wall units are an efficient and cost-effective way to cool and heat single rooms or areas in your home.