To confirm airflow through an electric furnace, which component may be used?

The sail switch is specifically designed to confirm airflow through an electric furnace. It operates by utilizing a lightweight sail or flap that is positioned in the airflow path. When the blower operates and air moves through the system, the airflow causes the sail to move, which then activates the switch. This activation indicates that sufficient airflow is present, allowing the furnace to operate safely and efficiently.

The sail switch is a vital safety component, as it prevents the furnace from running without adequate airflow. If airflow is insufficient, the switch will not engage, helping to protect the heating elements from overheating and potential damage.

While other components like thermostats, flow sensors, and pressure switches serve important functions within an HVAC system, they do not specifically confirm airflow in the same direct manner as the sail switch. The thermostat regulates temperature, the flow sensor measures the velocity of air, and the pressure switch detects pressure changes in the system, but none of these are directly tied to confirming the existence of airflow like the sail switch is.