Which system is used to cool the passenger area of a vehicle using a confined gas?

The system used to cool the passenger area of a vehicle that relies on a confined gas is the HVAC system, which stands for Heating, Ventilation, and Air Conditioning. This system plays a crucial role in regulating the interior climate of a vehicle, allowing passengers to experience comfortable temperatures regardless of external weather conditions.

In HVAC systems, the air conditioning portion cools the air using a refrigerant—a confined gas that circulates through various components, such as the compressor, condenser, evaporator, and expansion valve. As the refrigerant changes states from liquid to gas and back again, it absorbs and releases heat effectively, allowing the cabin air to be cooled down when necessary.

This makes HVAC systems essential for providing not only cooling but also heating and ventilation functions, contributing to overall passenger comfort. The other options, such as ASE (which typically refers to the National Institute for Automotive Service Excellence), EGR (Exhaust Gas Recirculation), and PCV (Positive Crankcase Ventilation), are related to engine performance and emissions, rather than directly managing the passenger space temperature.