An air handling unit (AHU) is a vital component of HVAC systems, responsible for circulating and regulating air within a building. Typically located in mechanical rooms or on rooftops, AHUs comprise fans, heating/cooling coils, filters, dampers, and controls. They intake outside air, filter and condition it, then distribute it through ductwork into occupied spaces. AHUs ensure indoor air quality by removing pollutants and regulating temperature and humidity levels. They play a crucial role in maintaining comfortable and healthy indoor environments in residential, commercial, and industrial buildings. Efficient AHU design and operation are essential for energy conservation and building sustainability, as they can significantly impact both comfort and operational costs.