How Air Handling Units and Rooftop Units Work

How Air Handling Units and Rooftop Units Work

Working Principle of Air Handling Unit:

Air handling unit is a kind of centralised air handling equipment, which is mainly used to adjust the temperature, humidity, cleanliness and other parameters of indoor air. Its working principle mainly includes the following aspects: firstly, outdoor air or indoor return air is sucked into the unit through the fan. After the air enters the unit, it is filtered through the filter to remove dust, pollen, bacteria and other impurities in the air and improve the cleanliness of the air. Next, the air is heated or cooled as needed. Heating is usually done by hot water, steam or electric heating, while cooling is generally achieved by cold water or refrigerant circulation. The heated or cooled air is then passed through a humidifier or dehumidifier for humidity adjustment to meet the requirements of indoor air humidity. Finally, the treated air is sent indoors through fans to achieve indoor air circulation and regulation.

Working Principle of Rooftop Unit:

A rooftop unit is a type of air-handling equipment that is installed on the roof, and it usually integrates cooling, heating, and ventilation. The working principle of a rooftop unit is somewhat similar to that of an air handling unit. First, a rooftop unit draws in air from outside through a fan or extracts return air from inside. Once the air enters the rooftop unit, it is filtered through a filter to remove impurities. Then, depending on the indoor temperature demand, the rooftop unit regulates the temperature of the air through a cooling system or a heating system. The cooling system usually adopts the principle of compression refrigeration, which absorbs heat from the air through the circulation of refrigerant, thus lowering the air temperature. Heating systems can use electric heating, hot water circulation or gas heating to raise the air temperature. In addition, the rooftop unit can also exchange indoor and outdoor air through the ventilation system to ensure the freshness of indoor air. Finally, the treated air is sent into the room through the air supply outlet to complete the air conditioning process.