A small air air handling unit (AHU) is a device used to condition and circulate air as part of a heating, ventilating, and air-conditioning (HVAC) system. It is typically used in commercial and industrial buildings to control the temperature, humidity, and air quality of the space. AHUs are designed to draw in air from the outside, filter it, and then supply it to the space. They also have the ability to return air from the space to the outside. AHUs are typically powered by electric motors, but they can also be powered by natural gas or steam. The size of an AHU depends on the size of the space it is intended to serve. Small AHUs are typically used in small spaces such as offices, while larger AHUs are used in larger spaces such as warehouses. Small AHUs are typically more energy efficient than larger units, and they are also easier to install and maintain.