Trane SWT3982 Reverse Flow Switch 105°F Open/ 95°F Close

The Trane SWT3982 is a reverse flow switch for HVAC systems. It operates on a bimetallic element that responds to temperature change. The switch opens when the supply air temperature is over 105°F, indicating a possibility of a reverse flow condition, where return air is being sucked into supply ductwork. On the other hand, it closes when the temperature is below 95°F, which means normal airflow. This switch is commonly used in Variable Air Volume systems to sense and block reverse airflow that will result in suboptimal cooling, discomfort to occupants and possible failure to equipment. The reverse flow conditions with the thereby optimizes system performance, increases energy efficiency, and improves overall comfort in the conditioned space.