Heating, Ventilation, and Air Conditioning (HVAC)
Heating, ventilation, and air conditioning (HVAC) is the vehicle system that heats, cools, dries, filters, and distributes cabin air. In everyday use, it is often called the climate-control system.
Boundary in an EV
Cabin HVAC covers occupant comfort, airflow, air recirculation, filtration, humidity control, and clearing condensation or frost from the glass. Its equipment can include a blower, filters, air-mixing doors, vents, a refrigerant compressor, heat exchangers, and one or more heat sources.
Battery conditioning and power-electronics cooling are separate thermal-management tasks. An EV may connect them to cabin HVAC through shared refrigerant or coolant circuits, but that shared hardware does not make the functions interchangeable. Cabin preconditioning therefore does not necessarily prepare the battery for driving or rapid charging.
Why it matters in an EV
HVAC draws energy from the traction battery while driving. Resistance heaters create cabin heat directly from electricity, whereas a heat pump can move heat from another source. The air-conditioning compressor may also run during cold-weather demisting because cooling the air removes moisture before it is reheated.
For system layouts, range effects, preconditioning, and controls, see Climate Systems in Electric Vehicles.