AAON rooftop units maintain constant supply air temperatures while adjusting airflow and compressor gas flow rates according to the cooling and heating load of the environment. With variable flow digital scroll compressors operating in a 10-100% capacity range and variable flow fans operating in a 30-100% range, an average energy savings of 50% can be achieved compared to rooftops with fixed flow and on/off capacity control.
Fan power consumption increases or decreases in proportion to the cube of the change in fan speed. When the fan speed is halved, the power consumption decreases to 1/8 of the original value.
For this reason, operating fans at variable flow rates is of great importance in terms of energy efficiency.
In packaged units, the gas circuit has a fixed flow rate, so the fan speed cannot be changed in most cases.
AAON rooftop units use variable flow compressors and variable flow fans, enabling them to operate not only at a fixed flow rate but also in conjunction with VAV devices or as single-zone VAV (SZVAV) systems.
Fan power consumption increases or decreases in proportion to the cube of the change in fan speed. When the fan speed is halved, the power drawn decreases to one-eighth of the original value.
For this reason, operating fans at variable flow rates is of great importance in terms of energy efficiency.
In packaged units, the gas circuit has a fixed flow rate, so the fan speed cannot be changed in most cases.
AAON rooftop units, which use variable flow compressors and variable flow fans, can operate not only in fixed flow mode but also in integration with VAV units or as single-zone VAV (SZVAV).
When selecting a vent, both the air flow rate and the throw distance are important. The greater the difference between the room temperature and the supply air temperature, the lower the air outlet distance should be. For example, when using an air outlet with a flow rate of 2000 m³/h, and the airflow rate decreases by 10%, 20%, or 30%, the supply air temperature must be adjusted between 30°C and 28°C to maintain a constant air outlet distance. Even if the diffusers in the project are not designed for a constant flow rate system, the device automatically adjusts the air supply temperature based on the ∆T (air supply temperature – room temperature) difference at the diffusers, ensuring the desired throw distances are achieved.
The rotary heat recovery AAON rooftop units used in the Mall of Istanbul and Volkswagen Arena projects operate as SZVAV and stand out for their low electricity consumption.
The AAON rooftops in the Kahve Dünyası project work in conjunction with VAV units.
The standard room pressure control feature allows the room to be kept at positive pressure, preventing the uncontrolled entry of unconditioned air into the room. The standard double-walled, 50 mm thick, heat bridge-free, hygienic panel structure reduces heat loss and gain from the device surface by 3 times compared to standard rooftop units.
When a signal is sent to the device by the BMS during a fire, the blowing fan stops, the economizer closes the fresh air, and the return air can be expelled outside with the exhaust fan.
More than 80% of rooftops manufactured by AAON, the market leader in commercial rooftop systems in the US, are variable flow.
In variable flow operation, the fan speed can be limited on the inverter to prevent problems with air outlet distances due to a decrease in air flow. During cooling, cold air is heavy and reaches the space easily. For this reason, the fan speed can be reduced to a minimum of 30% during cooling operation. In heating mode, since it is more difficult to lower the temperature of hot air, the fan speed is limited to approximately 75%.
In AAON rooftop units, dynamic airflow temperature control allows the airflow temperature to change as capacity decreases by specifying a reference range. For example, if a device set to a supply air temperature of 30°C is assigned a reference range of 2°C, the device will supply air at 28°C at minimum load.
Thanks to rotary-type heat recovery, which also enables moisture transfer, up to 83% of the energy from the exhaust air can be recovered.
Humidity control can be achieved without additional energy consumption using the hot gas reheat system with humidity removal option.
The AAON rooftops at the Volkswagen Arena project are equipped with a hot gas reheat humidity removal system.
It can operate at temperatures up to 52°C with 100% fresh air without recirculating air. The fresh air supply is temperature-controlled and can be delivered to the environment at room temperature via a rooftop unit (make-up air rooftop).
AAON rooftops are used in projects such as Medina Airport, Afghan American bases, and an energy plant in Iraq, where they can operate without recirculated air, taking in 100% fresh air up to 52°C and cooling it down to 15°C.
Due to all these features, AAON rooftops stand out as the preferred system solution for designers and are a top choice for green building applications.
AAON’s distribution in Turkey has been handled by ATLANTİK GRUP (www.atlantikgrup.com) for the past 10 years.