The economizer is an integrated device in each package AC units (usually in units over 5 ton) or air handling units that can have direct connection to the outside. The economizer system includes an air intake section and exhaust air section (with exhaust fan) both with a damper and actuator which work together relatively, that means if 80% outside air enters to the AC unit and space, then the 80% of the space air needs to be exhausted by the economizer’s exhaust section to balance the space air flow and to avoid over-pressurization. The concept of utilizing the AC units with economizer is:
- To provide a minimum required outside air based on the zone occupancy change which will be controlled by an occupancy sensor (CO2 sensor) in space and interlocking with the economizer trough the EMS (Energy Management System) for entire building or directly to AC unit for a single zone space to save energy.
- To use the outside air (OSA) to cool the space as a free cooling when the OSA temperature is low enough (lower than 68°F for comfort cooling). In this case compressor turns off and only fan works in unit. By free cooling can significantly save energy.