A packaged unit (also called a packaged system or rooftop unit/RTU) combines all HVAC components — compressor, condenser, evaporator, and often the air handler and heating system — into a single cabinet installed outdoors (typically on a rooftop or concrete pad beside the building).
Unlike split systems where components are divided between indoor and outdoor units, everything in a packaged unit is in one place. This simplifies installation and service, reduces refrigerant line length, and makes rooftop installation on commercial buildings practical.
Packaged units are dominant in light commercial applications (retail stores, small offices, restaurants) and are common in single-story residences in warmer climates where interior space is at a premium. They are available in gas/electric configurations (gas heat, electric cooling), heat pump configurations, and all-electric configurations.