A RTU package unit is a self-contained, pre-engineered, and factory-assembled system that is used to condition the air in a building. It typically consists of a fan, a heating and/or cooling coil, and a filter. It is designed to be installed outdoors and can be used to heat, cool, humidify, dehumidify, and filter the air in a building. RTU package units are ideal for buildings that require precise temperature and humidity control, such as hospitals, laboratories, and schools. They are also popular in commercial buildings, such as office buildings, warehouses, and retail stores. RTU package units are typically more efficient than traditional split systems, and they are easier to install and maintain. They also require less space than traditional split systems, making them a great choice for tight spaces.