HVAC package unit is a type of air conditioning unit is made of cooling and heating “furnace”systems that are encased in big box. There are two sets of openings, one pair on side and second on the bottom of box, these are supply and return connection of air ducts connection. People choose this type system to save space inside of building or any other structure. This package unit are installed on the roof of house or any other building settings, usually on commercial. The benefit of this type air conditioning unit is to save space inside of building, second the noise of AC dissipate in open space of roof.