How does economizer damper control logic decide when to open or close?

How does economizer damper control logic decide when to open or close?

• A. It compares outdoor air conditions (temp/humidity) to cooling needs and opens when OA helps meet cooling; closes when not needed.
• B. It compares indoor conditions and opens when occupants are present.
• C. It opens only when inside temperature is high and closes when outside air is cold.
• D. It opens randomly.

Answer: (A)

Economizer damper control is about using outdoor air to meet part of the cooling load whenever outdoor conditions can actually help. The controller compares outdoor air conditions (temperature and humidity, sometimes enthalpy) to what the building cooling needs are. If outdoor air is cool and dry enough to reduce the coil cooling required, the damper opens to bring that air in. If outdoor air wouldn’t provide a cooling benefit (or would make humidity control worse), the damper stays closed or only partially opens. It isn’t driven by occupancy or random chance; it’s a deliberate check of whether outdoor air can meaningfully reduce the cooling load, and it closes when it can’t.

Economizer damper control is about using outdoor air to meet part of the cooling load whenever outdoor conditions can actually help. The controller compares outdoor air conditions (temperature and humidity, sometimes enthalpy) to what the building cooling needs are. If outdoor air is cool and dry enough to reduce the coil cooling required, the damper opens to bring that air in. If outdoor air wouldn’t provide a cooling benefit (or would make humidity control worse), the damper stays closed or only partially opens. It isn’t driven by occupancy or random chance; it’s a deliberate check of whether outdoor air can meaningfully reduce the cooling load, and it closes when it can’t.