In a packaged system, all equipment is built into an outdoor unit, usually on a concrete slab or other platform. The "package" that gives it its name provides central air conditioning during the summer and heat in colder months.

The efficiency of packaged systems are rated using SEER (for cooling efficiency), AFUE% (for gas heating efficiency) and HSPF (for heat pump efficiency). Ductwork is required to transfer the heated or cooled air throughout the home.