A Closer Look at Air Handler Unit Functions

A Guide For Choosing The Right HVAC Installation Company

What is an Air Handler Unit?

An air handler unit, also known as an AHU, is a crucial component of a heating, ventilation, and air conditioning (HVAC) system. It is responsible for circulating conditioned air throughout a building, ensuring proper airflow, and maintaining a comfortable indoor environment. The AHU is typically located in a mechanical room or an equipment closet and connects to the ductwork system that distributes air to various parts of the building.

Components of an Air Handler Unit

An air handler unit consists of several essential components that work together to perform its functions. Let’s take a closer look at each of them:

1. Blower Motor

The blower motor is a crucial part of the air handler unit and is responsible for generating the airflow. It pulls air from the return ducts and pushes it through the other components of the AHU, ensuring adequate circulation. The blower motor’s speed can be adjusted to control the volume of airflow, allowing for customization based on the building’s requirements.

2. Fan and Fan Speed Control

The fan works in conjunction with the blower motor to move the air effectively. It helps distribute the conditioned air throughout the ductwork system and into different areas of the building. The fan speed control allows for adjustments to achieve the desired airflow and temperature distribution.

3. Evaporator Coil

The evaporator coil is responsible for cooling the air. It contains a refrigerant that absorbs heat from the air passing over it, cooling the air in the process. As the warm air comes into contact with the cold coil, moisture from the air condenses onto the coil, further reducing humidity levels.

4. Heating Elements

In addition to cooling, an air handler unit may also have heating elements. These elements can provide supplemental heat when needed, especially during colder months or in areas where additional heating is required.

5. Air Filtration System

The air filtration system within the AHU is responsible for removing dust, allergens, and other particles from the air. It helps maintain good indoor air quality by capturing and trapping pollutants before the air is distributed throughout the building. Regularly changing the air filters is crucial to ensure their effectiveness and prevent the accumulation of dirt and debris.

Airflow and Filtration

One of the primary functions of an air handler unit is to provide proper airflow and filtration. The blower motor, fan, and air filtration system all work together to ensure a continuous supply of clean, conditioned air to the building’s occupied spaces. Without adequate airflow, comfort issues may arise, and indoor air quality can deteriorate, leading to potential health problems.

The air filtration system helps remove contaminants, including allergens, dust, and pollutants, from the air. This can greatly benefit occupants, particularly those with respiratory conditions or allergies. Regular maintenance and filter replacement are necessary to ensure optimal filtration efficiency.

Heating and Cooling Function

The air handler unit plays a vital role in both heating and cooling processes. It helps cool the air by passing it over the evaporator coil, where heat is absorbed and removed. In the case of heating, if the AHU has heating elements, it warms the air before distributing it to the desired areas.

By providing both cooling and heating capabilities, an air handler unit allows for year-round comfort and climate control, regardless of external weather conditions.

Humidity Regulation

An air handler unit also helps regulate humidity levels within a building. During the cooling process, as warm air comes in contact with the cold evaporator coil, moisture condenses, reducing the humidity in the air. This can help create a more comfortable indoor environment and prevent issues such as mold growth and excessive moisture.

Energy Efficiency

An energy-efficient air handler unit can significantly impact the overall energy consumption and operating costs of a building. Components like variable-speed motors and advanced control systems allow for precise adjustment of airflow and temperature, resulting in optimized energy usage.

Regular maintenance, including cleaning coils and replacing filters, is essential to ensure the air handler unit operates efficiently. Proper maintenance can also extend the unit’s lifespan and prevent unnecessary breakdowns or repairs.

Importance of Regular Maintenance

Regular maintenance is vital for the proper functioning and longevity of an air handler unit. It includes tasks such as cleaning or replacing filters, inspecting and cleaning coils, lubricating moving parts, and checking electrical connections. By performing these maintenance activities, potential issues can be identified and addressed early, preventing costly repairs and ensuring optimal performance.

Additionally, regular maintenance helps maintain good indoor air quality, reduces energy consumption, and ensures the air handler unit operates at its full capacity. It is recommended to schedule professional maintenance at least once a year, preferably before the start of the cooling or heating season.


The air handler unit is a crucial component of a building’s HVAC system, responsible for circulating conditioned air and maintaining a comfortable indoor environment. Its components work together to ensure proper airflow, filtration, heating, cooling, and humidity regulation. Regular maintenance is essential to keep the air handler unit operating efficiently and to prevent issues that can affect comfort, indoor air quality, and energy consumption.

Publisher’s Details:

ICE Air Conditioning & Plumbing
2620 Regatta Dr Suite 102, Las Vegas, NV 89128, United States
(866) 460-4372

The air handler unit is the heart of your HVAC system. For reliable HVAC repair and maintenance, trust the experts at ICE. [Link] Keep your air handler running efficiently, providing comfort, and ensuring clean, healthy indoor air.

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