Different Types of Air Handling Units and Their Applications
When you walk into a hospital, a pharmaceutical plant, a shopping mall, or even a well-maintained office building, one thing is almost always working silently behind the scenes — an Air Handling Unit. Most people never notice it. But the moment it stops working, everyone does. At Airtree, we have spent years engineering and supplying air handling solutions across some of India's most demanding environments. Over time, one question keeps coming up from facility managers, MEP consultants, and project engineers alike: "Which type of AHU is right for my application?"
What Exactly Is an Air Handling Unit?
An Air Handling Unit, commonly called an AHU, is a piece of equipment that conditions and circulates air as part of a Heating, Ventilation, and Air Conditioning (HVAC) system. Think of it as the lungs of a building — it draws in air, treats it (cools, heats, filters, dehumidifies), and then delivers it to occupied spaces through a duct network.
A typical AHU consists of:
Fans/blowers to move air through the system
Cooling or heating coils to adjust air temperature
Filters to remove dust, particulates, and allergens
Dampers to control airflow volumes
Drain pans to collect condensate
An insulated casing to prevent energy losses
The key differentiator between AHU types is not just the shape or size — it is the application they are designed for, the airflow capacity they handle, and where they are physically installed within a building.
The Main Types of Air Handling Units
1. Vertical AHU
The Vertical AHU is one of the most widely used configurations in commercial and institutional buildings across India. As the name suggests, all the internal components — the fan section, coil section, and filter section — are stacked vertically within the unit's casing. This allows the AHU to have a smaller floor footprint compared to its horizontal counterpart, making it a practical choice where floor space is limited but ceiling height is available.
How it works: Air enters from the bottom or side of the unit, passes through the filtration and coil sections in a vertical path, and exits through the top or the side into the ductwork.
Read More....