The main difference is the equipment arrangement.

A rooftop packaged unit places the refrigeration system and air-handling components inside one outdoor cabinet, while a split HVAC system separates the indoor and outdoor equipment.

How does a rooftop unit work?

A rooftop unit is normally connected directly to the building's supply and return duct system. Conditioned air leaves the rooftop unit, travels through the duct network and returns back to the unit.

How does a split system work?

A split system normally uses an outdoor condensing unit or heat pump connected by refrigerant piping to an indoor air handler, furnace or evaporator coil.

Which system is better?

Neither system is automatically better for every project.

Rooftop units can be very practical for commercial buildings with roof access and central ductwork, while split systems may provide more flexibility where indoor air handlers need to be located inside mechanical rooms, attics or other building spaces.