Stepper Motor Actuator for HVAC Blend Door – A Review

Air conditioning and heating system in a car are very necessary accessory. In a general air handling system, the air duct has the heater core mounted on the evaporator core. The temperature of the air depends on the amount of mixing of the air, which passes through the heating core and then through the evaporator. The passage of air through the heater core is controlled by a flap which directs the air. In a conventional air conditioning and heating system in the car, the movement of the flap is manually. The passenger inside the vehicle adjust the flap according to their comfort. Heating, ventilation, and air conditioning (HVAC) is a type of technology which are being used extensively in vehicles, residential structures and office buildings for the environmental comfort of the human. HVAC mainly gives temperature comfort. This system also provides better indoor air. In the case of an automobile HVAC system it has all the same components which are similar to a conventional air conditioning and heating system. Only difference, the movement of the blend door are with the help of an actuator. The actuator would move the blend door constantly to mix the air between the hot air from the heating core and cold air from the evaporator to maintain the air temperature. Generally, in an HVAC door blend actuator, electro mechanical actuator is used. Electro mechanical actuator can be used in many places as they can generate motion which are mainly required by different valve actuation. The paper reviews about stepper motor being used in the actuator.