A rooftop AC/Heater unit is a type of air conditioning and heating system that is installed on the roof of a building. This type of system is ideal for larger buildings, such as office buildings, warehouses, and multi-family dwellings, where it can provide efficient cooling and heating to multiple rooms. The unit typically consists of an outdoor condenser, an indoor evaporator, and a fan to circulate the air. The condenser is responsible for cooling the air, while the evaporator is responsible for heating the air. The fan helps to circulate the air throughout the building, providing consistent temperatures in each room. The rooftop AC/Heater unit is a great way to keep a building comfortable all year round, while also being energy efficient and cost effective.