GreenTrol Automation has delivered application-specific controllers with integrated thermal dispersion airflow measurement since 2009. The OAC Series offers a turnkey outdoor airflow control solution for small air-handling units, makeup air units, and single- or multi-zone demand-controlled ventilation systems. Because outdoor air is code-required and essential for indoor air quality, thermal comfort, and occupant health, improper control can lead to poor IAQ, increased energy consumption, and inadequate temperature and humidity control.
Light commercial HVAC systems account for more than 50% of today’s heating and ventilating needs. Although energy efficiency ratios have dramatically improved over the past several decades, outdoor air ventilation control has been ignored. Proper OA ventilation is essential for maintaining IAQ, thermal comfort, and building code compliance. Without accurate control, systems risk:
Conventional OA control approaches often fail, leading to ventilation errors exceeding 50%. Common issues include:
By integrating GreenTrol solutions into your HVAC system, you can:
From comfort and code compliance to energy efficiency, GreenTrol ensures your HVAC systems perform the way it was meant to. With accurate, reliable, intuitive solutions, your team can focus on what matters—knowing your system is running at its best.

CO2, Relative Humidity, and Temperature

Airflow, Temperature

Thermal Imaging

Airflow, Temperature and Humidity

Display, Alarm and Analog to RS-485 BACnet/Modbus Bridge

Probes and Controllers