Dedicated Outdoor Air Systems

Dedicated Outdoor Air Systems

A dedicated outdoor air system (DOAS) is a unit supplying cooled, dehumidified outside air to the building in summer and heated outside air in the winter. The system can also include a total energy wheel. An energy recovery wheel offers up to 80% total effectiveness reducing the heating and cooling capacity requirement of the DOAS unit significantly.




Pre-engineered rooftop ventilators condition and deliver 100% outside air or mixtures of outdoor air and return air to a building. This unit is ideal for 100% outdoor air, variable air volume and single zone applications.

  • 500 to 18000 cfm
  • Up to 3 in. wg (ESP)
  • 3 to 70 tons cooling capacity
  • 75 to 1,200 mbh heating capacity
  • Cooling options: packaged direct expansion, chilled water, air-source heat pump, and split direction expansion with or without remote condenser on select models
  • Heating options: indirect gas, electric, and hot water


The ERCH combines the benefits of the total energy wheel with supplemental cooling and/or heating. The result is a product that is specifically designed to condition 100% outdoor air to desired supply conditions. Model ERCH offers a wide variety of configurable options from intake and discharge orientations to factory tested and proven control sequences.

  • 1,000 - 10,000 cfm
  • Up to 1.75 in. wg
  • Cooling options: split direct expansion, chilled water, water-source heat pump, or evaporative cooling
  • Heating options: indirect gas, electric, hot water, or water-source heat pump


Model ERT offers the benefits of a total energy wheel and cooling coil with a wrap-around heat pipe and/or heating. The result is a unit designed to be the most efficient product for conditioning humid outdoor air to near room conditions.

  • 2,000 - 10,000 cfm
  • Up to 1.75 in. wg
  • Cooling options: split direct expansion or chilled water
  • Heating options: electric or hot water

Dedicated Outdoor Air Systems Controls

DOAS systems offer control options for efficient operation including integration into building management systems. These controls come pre-programmed from the factory and are easily configured in the field.

Learn more about DOAS controls.