The definition of a split unit AC is a type of air conditioning system that is composed of two separate components. The first component is an outdoor unit, which contains the compressor, condenser, and fan. The second component is an indoor unit, which contains the evaporator and blower. The two components are connected by refrigerant lines and electrical wiring. Split unit ACs are a great choice for homes and businesses that need cooling in multiple rooms, as each indoor unit can be controlled separately. They are also more energy efficient than traditional central air conditioning systems, as they can be used to cool specific areas rather than the entire building. Split unit ACs are also relatively easy to install and maintain, making them a popular choice for many homeowners.