An Air Handling Unit (AHU) is a crucial component of HVAC systems, responsible for regulating and circulating air within buildings to maintain indoor air quality and comfort. It consists of a large metal box containing a blower, heating or cooling elements, filters, and dampers. The AHU draws in outside air, filters it, and either heats or cools it before distributing it throughout the building via ductwork. By managing air flow, temperature, humidity, and cleanliness, AHUs ensure a controlled and healthy indoor environment, making them essential for commercial and industrial facilities.