Automotive air-conditioning technicians install and repair air-conditioners and parts, such as compressors, condensers, and controls. These workers must be trained and certified in handling refrigerants. An HVAC Technician, or a Heating, Ventilation and Air Conditioning Technician, installs and repairs various air quality systems. Their main duties include locating and diagnosing maintenance problems on equipment, conducting warranty services and quickly performing emergency repairs on certain equipment items.