Function and Purpose:
The primary purpose of an ADU is to handle the circulation, filtration, cooling, heating, and humidity control of air within a building.
It acts as the central point for air processing and ensures the delivery of clean and comfortable air to different zones within the building.
Construction and Housing:
ADUs are typically housed in a metal enclosure to protect the internal components from external elements and to dampen noise. The enclosure often includes insulation to prevent thermal losses or gains.
Air Filters:
Air filters are crucial components of ADUs, responsible for removing airborne particles, dust, and pollutants. High-quality filters ensure better indoor air quality and protect the system from contamination.
Fans and Blowers:
ADUs contain fans or blowers that facilitate air movement through the unit. These fans are designed to provide the necessary air pressure to overcome system resistance and deliver air to various sections of the building.
Cooling and Heating Elements:
To control the air temperature, ADUs may have cooling and heating elements. Cooling coils help lower the air temperature, while heating coils raise it. These elements play a vital role in maintaining the desired indoor climate.
Humidification and Dehumidification:
In environments where humidity control is essential, ADUs may include humidifiers and dehumidifiers. These components add or remove moisture from the air to maintain the desired humidity levels.
Dampers:
Dampers are movable plates or vanes that regulate the airflow within the ADU and the distribution ducts. They help balance the air supply and return to achieve proper ventilation.
Controls and Sensors:
Sophisticated ADUs come equipped with control systems and sensors to monitor and adjust the air distribution process. These controls optimize energy efficiency, air quality, and comfort.
Energy Efficiency:
Modern ADUs focus on energy efficiency through advanced components, variable speed drives, and heat recovery systems. Energy-efficient ADUs can significantly reduce operating costs and environmental impact.
Airflow Capacity:
The airflow capacity of an ADU is measured in cubic feet per minute (CFM) or cubic meters per hour (m³/h).
The capacity must be adequate to meet the ventilation requirements of the building and its occupants.
Static Pressure:
Static pressure measures the resistance to airflow within the ADU and the ductwork. It is crucial to ensure that the fan can overcome this resistance and deliver the required airflow to different zones.
Noise Levels:
Noise considerations are vital in commercial and residential settings. Manufacturers often provide sound data for their ADUs, helping consumers choose units with acceptable noise levels for their intended applications.
Maintenance and Serviceability:
Easy access to internal components is essential for maintenance and repair purposes. Well-designed ADUs allow technicians to service filters, coils, fans, and other parts without difficulty.
Safety Features:
ADUs may include safety features like pressure switches to prevent overheating, frost sensors to protect cooling coils, and airflow sensors to detect blockages.
