A Packaged Terminal Air Conditioner (often abbreviated PTAC) is a type of self-contained heating and air conditioning system commonly found in hotels, motels, senior housing facilities, hospitals, condominiums, apartment buildings, add-on rooms & sunrooms. Many are designed to go through a wall, having vents and heat sinks both inside and outside. Different standard dimensions are found in the market including 42×16 inches (1067 x 406 mm), 36x15 inches, and 40x15 inches.