What is a split system?

A split system pairs an outdoor condenser unit with an indoor air handler or furnace, connected by refrigerant lines, power cables, and a condensate drain. The outdoor component cycles refrigerant and exhausts heat, while the indoor unit distributes cooled or heated air through ducts to rooms throughout the home. This arrangement is the standard residential HVAC setup across Phoenix and most of North America.

The split design offers practical advantages over alternatives. Unlike package units (which house all components in a single outdoor box), split systems keep the noisier compressor outside and allow the quieter indoor handler to fit in attics, basements, or utility closets. Unlike mini-split ductless systems (which use individual indoor head units per room), full splits use existing ductwork to serve the entire home from one central air handler.

When installing or replacing HVAC equipment, technicians size the outdoor condenser capacity to match the indoor unit and the home's heating or cooling load. The refrigerant charge, airflow, and electrical connections must be balanced for efficiency. Most split systems run on 240-volt power and require professional installation. In Phoenix's hot climate, split systems are the workhorse for air conditioning, though many models include heat pump capability for mild winters. Find local contractors who service and install split systems.