| Topic | Summary |
| HVAC legislation |
In most countries, any person who services an air conditioning system must be separately accredited to comply with local environmental protection legislation, or under close supervision of an accredited person. |
| Vehicle heating & ventilation systems |
To improve passenger comfort and safety, fresh air is drawn from outside ducts and directed to the passenger compartment. Incoming air can be heated by passing over a small heating core connected to the engine's cooling system. |
| Basic air-conditioning principles |
Heat transfer can take place by one of three methods, conduction, convection and radiation. |
| Air-conditioning capacity |
Latent heat is the amount of heat required to be added to a substance or removed from a substance to bring about a change of state. |
| Air-conditioning refrigerant |
The refrigerant removes heat from the vehicle interior and transfers it to the outside air in a continuous cycle of vaporization and condensation. |
| Humidity | Reducing the temperature of the air also reduces its humidity. Cold air will not hold as much water vapor as warm air. |