HVAC Duct Air Flow Switch 250V 8A Stainless Steel Paddle Description KAFS Series Flow Switch. HVAC Air Duct Mounted IP65 250V 8A Stainless Steel Paddle Airflow Switch. KAFS series adjustable air flow paddle switch is used to control and monitor air and non-aggressive gas flow in ducts. Well-suited for air ducts, air conditioning and air handling systems. Application Control and monitor air and non aggressive gases flow in ducts, chambers, etc.,of heating, cooling, and air