What is an Air Handling Unit and What is its Purpose?

What is an Air Handling Unit and What is its Purpose

Try and recall the last time you walked into a building that was hot and humid and felt good when you came in and the cool wind started blowing. For example, at times when it is perpetually icy and you walk in and feel instantly warm. Have you ever been curious as to how it is these air conditioners are capable of controlling the climate? That would be the Air Handling Unit, that is AHU for short.

That’s why today’s article concerns AHUs. The more generalized explanation of what they are and how they function is not important but emphasizes their importance in maintaining the indoor spaces comfortable and pleasant.

What is an Air Handling Unit?

An air handling unit or AHU, for short, is the main device of a building’s HVAC – heating, ventilation, and air conditioning – system. Visualize a big metal box in the place it is sheltered beneath the floors of the building—be it in a utility room, basement, or rooftop.

What is an Air Handling Unit

In this box, one can notice a careful arrangement of components that have been engineered to perfection and they are the ones that help to regulate the temperature, humidity, and air quality of the building.

Components of an AHU


These components perform an important function of keeping indoor air quality high by removing several airborne particles such as dust, pollen, mold spores, and other microscopic contaminants.

Heating and Cooling Coils

These are coil-shaped structures that the air passes through, which adjusts its air temperature. In the summer the cooling coils cool down the air and help through the heat, and in the winter the heating coils warm up the air for combating the cold temperatures outside.


The AHU fans are the major power for the distribution of air within the system as a whole. They are always on the go, pulling the air toward the vents and circulating it across different parts of the building.

The fact that fans are regulating the circulation of air inside the building, leads to good temperature regulation and fresh, oxygenated air.

Humidifiers and Dehumidifiers

Such components are in charge of the water vapor control within the building. Humidifiers can be utilized to increase the air’s moisture when it’s too dry so that you do not experience scratchy throats or dry skin.

Conversely, dehumidifiers absorb extra moisture from the air during humid conditions so that people do not experience the sticky and uncomfortable feeling of high humidity.


Dampers are adjustable slats or doors located within the HVAC ductwork which regulates the air flow. They allow the direction of the air to be adjusted by varying the amount of air directed to the zone of the building for instance.

Purpose of an AHU

Temperature Control

The primary role of AHU is to maintain the indoor temperature at the necessary level, regardless of whether the weather outside is hot or cold. It performs this by either warming or cooling the air and then putting it in all the rooms of the building.

Purpose of an AHU

The AHU stabilizes the temperature which in turn guarantees the comfort of workers, students, and people in general as they will not be too hot or cold when working, learning, or relaxing inside the building.

Air Quality Assurance

While air pollution is an issue in many districts, the AHU functions to make the indoors more secure and safe to breathe than the outside air. It does it by capturing dust, allergens, pollutants, and other toxic particles from the air before they finish the circuit in the building.

These enable the decrease of respiratory concerns and other health problems connected to an unhealthy atmosphere.

Humidity Regulation

the AHU regulates the humidity levels within the developed building to make the internal environment comfortable. In the case of a lack of humidity, it can add moisture to the air which usually helps to get rid of the discomfort of dry skin and throat irritation.

On the other hand, in humid climates, it can remove extra moisture that can help in controlling the growth of mold and mildew as well as make the air fresh instead of feeling sticky.


Effective ventilation is a basic indoor air quality element, which enables to avoid the accumulation of stuffy air, odors, and pollutants. The AHU helps the ductwork system by bringing fresh air in from the outside and circulating it through the building while at the same time exhausting stale air to the outside.

Through this continuous inflow and outflow of air, replenishment of the indoor air’s oxygen content, removal of indoor pollutants, and thereby creating a healthier and more satisfying indoor environment for the occupants is achieved.


In conclusion, the Air Handling Unit may not boast the glamour or grandeur of its more conspicuous counterparts but make no mistake—it is the beating heart of any modern building, the linchpin upon which comfort, health, and well-being hinge.

From regulating temperature and humidity to purifying the air you breathe, the AHU performs its duties with quiet efficiency, ensuring that you can work, play, and live in a space that is not just tolerable, but truly transcendent.