An air package unit is a self-contained heating and cooling system that is typically used in commercial and industrial buildings. It is a single unit that houses both the heating and cooling components, such as an evaporator coil, condenser, compressor, and blower, in one cabinet. This type of system is often used in large buildings, such as office buildings, warehouses, and factories, where the heating and cooling needs are more complex than a single residential unit can provide. The air package unit is a cost-effective and efficient way to provide heating and cooling to a large space. It is also relatively easy to install and maintain, making it a popular choice for many businesses.