A packaged HVAC system is a self-contained unit that contains both the heating and cooling components of an air conditioning system in one package. These systems are typically used in small buildings or as a supplement to an existing HVAC system.

A packaged unit contains the supply and exhaust fans, the compressor, the condenser, evaporator, heating coil, and air filters. Thus, a packaged unit runs the entire refrigeration cycle and is able to supply the conditioned air to a building. There are many different types and sizes and they have many different control options such as constant volume units or VAV units.

There are two main types of packaged systems: air-source and ground-source. Air-source systems use the outdoor air to heat and cool the building, while ground-source systems use the constant temperature of the Earth to heat and cool the building.

Packaged systems are typically installed on the roof or outside wall of a building and can be used to condition a single room or an entire building. They are convenient because they require minimal ductwork and can be easily installed in buildings where it is difficult to install traditional HVAC systems.

However, they may not be as efficient as some other types of HVAC systems and may not be suitable for larger buildings or those with high heating and cooling demands.