.png)
Air Handling Units: Structure, Functions, and Applications
An air handling unit, or AHU, is a vital component in heating, ventilation, and air conditioning (HVAC) systems, responsible for regulating and circulating air within buildings. It ensures thermal comfort and indoor air quality by managing air temperature, humidity, cleanliness, and movement through a controlled ventilation process.
What Is an Air Handling Unit?
An air handling unit is a large metal box that contains various mechanical components designed to condition and distribute air. Typically located in basements, rooftops, or dedicated mechanical rooms, AHUs are connected to ductwork that delivers treated air throughout a building and returns stale air back for reconditioning or exhaust.
Key Components of an Air Handling Unit
Filters: Remove dust, pollen, and other airborne particles to maintain air quality.
Heating and Cooling Coils: Use hot water, steam, or chilled water to adjust the air’s temperature as required.
Fans and Blowers: Circulate air across the coils and through the building’s ventilation ducts.
Dampers: Regulate the amount of fresh outdoor air entering the system and control airflow direction.
Humidifiers/Dehumidifiers: Maintain appropriate indoor humidity levels.
Mixing Chambers: Blend return air with fresh outdoor air to optimize efficiency.
Types of Air Handling Units
Modular AHUs: Custom-built for large commercial or industrial facilities where specific configurations are required.
Compact AHUs: Preassembled units ideal for smaller spaces or residential settings.
Rooftop Units (RTUs): Installed on building roofs to save interior space and simplify maintenance access.
Packaged Units: Include all components within a single casing, often used where indoor space is limited.
Functions and Benefits
Temperature Control: Maintains desired indoor temperature year-round through efficient heating and cooling.
Ventilation: Brings in outdoor air and expels stale indoor air, improving air freshness and oxygen levels.
Air Quality Management: Filters and purifies air to remove contaminants and allergens.
Humidity Regulation: Prevents excessive dryness or moisture buildup, which can affect occupant comfort and building integrity.
Energy Efficiency: Advanced AHUs can include energy recovery systems that reduce heating or cooling demand by reusing energy from exhaust air.