What is an Air Handling Unit (AHU) & It's Function? - TCW Group

An air handling unit (AHU) is a common equipment found within various industrial or commercial environments. Its primary function is to circulate fresh air into different areas of a building.

These units form the core of the overall HVAC (heating, ventilating, and air conditioning) system, as they are responsible for managing ventilation. AHUs take in both outdoor air and indoor air (the air already present within the building), filter it, and adjust its temperature and humidity. After making these adjustments, they distribute a refreshing and comfortable supply of air conditioning through arranged ductwork to the various rooms within the structure.

The essence of an AHU is particularly noticeable in spaces such as hotel dining areas, function venues, eateries, and conference centers where natural ventilation is limited due to substantial numbers of guests present at once.

Moreover, AHUs serve as an optimal solution for environments adhering to strict hygiene standards, such as manufacturing plants, clean rooms, surgical theatres, and research laboratories. They also effectively ventilate areas equipped with unique heating setups, including underfloor heating or radiators for cooling.

AHUs can be installed on rooftops, in basements, or attached outside building walls. They generate both cooled and heated air, routing this air into various rooms for temperature regulation. Unlike typical industrial air conditioning systems, AHUs are frequently tailored according to the specific needs of each individual or building.

Customization options for AHUs often include internal mounting of filters, humidifiers, and various components that help in regulating air temperature, humidity, airflow, and cleanliness.

Air intake

This component draws in outside air, cleans it, and distributes it throughout the interiors. Furthermore, it can also recycle indoor air.

Filter

The filtration equipment employed will vary in its ability to retain particles, viruses, bacteria, odors, and other air contaminants based on air purity standards. Regular filter replacements are necessary for optimal performance.

Blower or fan

This electromechanical system moves the air out of the AHU and into ductwork for distribution throughout the building.

Heat exchangers

Heat exchangers facilitate temperature transfer between two fluids - in this scenario, air and coolant - through a solid barrier.

Cooling coil

As air moves through the cooling coil, it becomes cooler. The condensation that may occur during this process is collected in a condensate tray via a built-in droplet separator.

Plenums

Plenums strategically placed in void areas serve to homogenize airflow effectively.

The primary aim of an AHU is to enhance energy efficiency. By harnessing waste heat and reusing it through specialized "run-around" coils alongside heat exchanger cooler units, the system minimizes the load on heating coils while optimizing energy consumption.

During the cooling phase, AHUs blend indoor and outdoor air to mitigate drastic temperature differences when approaching the cooling coil, thereby maximizing energy-efficient cooling results.

To conclude, one of the significant advantages of AHUs lies in their capacity to be installed in multiple units within a single external area. While outdoor commercial air conditioning units are usually placed on rooftops or exterior walls of structures, internal units require individual installations in each room.

In addition to installation complexity, maintaining each indoor unit incurs expense and time. AHUs, however, can be collectively maintained at an external site, streamlining maintenance efforts.

However, there are limitations. If an AHU malfunctions, it can lead to a total loss of air conditioning throughout the building, highlighting the necessity of having multiple AHUs for backup support.

For further information about Air Handling Units (AHUs), don't hesitate to connect with our dedicated consultants.

Explore our range of Air Handling Units created and assembled by the TCW Group.