What happens to outdoor dampers when a freeze stat trips in an air handler?

When a freeze stat trips in an air handler, it is designed to protect the system from low temperatures that could lead to freezing of the coils. In this situation, the outdoor dampers will be fully closed with the fan off to prevent cold air from entering the system. This configuration helps to isolate the coil from the outside environment, thereby reducing the risk of ice formation on the coil and preventing potential damage to the system.

By shutting the dampers and turning off the fan, the system minimizes the circulation of cold air that could exacerbate the freezing conditions. Keeping the fan off also prevents the potential for cold air to be circulated throughout the space served by the HVAC system, ensuring that the indoor environment remains at a safer temperature while addressing the freezing issue. This action is crucial for maintaining the integrity and functionality of the air handling system.