Primarily, there are two types of air handling units (AHUs) utilized for regulating airflow in HVAC systems: the 'blow-through' and the 'draw-through' AHUs. The blow-through AHU comprises a fan that pushes the air through the mixing box, cooling coil, and filters whereas a 'draw-through'AHUs pull the air.
AHUs can be classified based on their orientation, which includes vertical, horizontal, ceiling-suspended, or ground-mounted AHUs.
Based on the type of space, there are two types of AHUs – Packaged and modular units. Packaged units are typically used in smaller buildings, while modular units are commonly found in larger commercial or industrial applications.