HVAC&R stands for heating, ventilation, air conditioning and refrigeration. HVAC/R generally refers to the mechanical systems used in the heating, cooling and ventilation of indoor environments. The people who service them are called HVAC/R technicians. The trade involves installing, maintaining and repairing climate-control devices such as air conditioners, furnaces, refrigerators and freezer units.
Industrial and commercial HVAC-R systems include such components as air ducts, piping, vents and thermostats. Technicians are responsible for installing and maintaining these systems and ensuring that each part is functioning correctly. Refrigerators, freezers and air conditioners operate with liquid refrigerants to expel heat from indoor areas.