Install the “B‑18 Airflow Switch Knob” to ensure accurate control of your airflow‑switching system - ideal for dehumidifiers, ventilation equipment, or HVAC setups requiring reliable airflow detection and safety. An airflow switch (also known as a flow switch or sail switch) activates or deactivates in response to air movement: when sufficient airflow is detected, it allows the system to operate; when airflow is lost or insufficient, it can trigger a shutdown or safety alert.