18/03/2022
☞How Does AC Work in a Car? ➤
The air-conditioning system in a car works by manipulating refrigerant between a liquid and a gaseous state. As the refrigerant changes states, it absorbs heat and humidity from the vehicle and allows the system to give off cool, dry air.
To change the refrigerant between a liquid and a gaseous state, the air-conditioning system works to control pressure and temperature.
☞AC System Refrigerants ➤
In the past, automotive air-conditioning systems used R-12 as the refrigerant. R-12 (aka Freon) is a very effective CFC-based (chlorofluorocarbon) refrigerant that is not flammable and not poisonous to humans. During the late 1980s, scientists discovered that widespread usage of R-12 was damaging the earth’s ozone layer.
Manufacturers transitioned to R-134a in the mid-1990s. R-134a is an HFC-based (hydrofluorocarbon) refrigerant that does not have the ozone destroying properties of R-12/Freon. The newest refrigerant is R-1234yf, which produces fewer greenhouse gases. Europe requires the use of R-1234yf, and it will likely be the new standard in the United States in the near future.
☞HOW DO AIR CONDITIONING SYSTEMS WORK IN A CAR?➤
☞ Car AC System Parts➤
Automotive air-conditioning systems have a few key components. Listed below are the main parts and their roles:
☞Compressor➤
Power unit of the system that separates the low-pressure side from the high-pressure side
Takes in low-pressure gas and compresses it into high-temperature/high-pressure gas
Mounted to front of engine and driven by serpentine belt
☞Condenser ➤
Reduces temperature of refrigerant while it maintains high pressure
Refrigerant changes from gaseous state to liquid state as it cools
Similar to the engine radiator, it uses forced air (fan or vehicle movement) to transfer heat
Mounted in front of vehicle, behind grill
☞Dryer ➤
Removes water from the refrigerant using a desiccant (drying agent)
Has some system-filtering properties
Mounted on high-pressure side of system, between condenser and metering device
Metering Device
Either expansion valve or fixed or***ce tube
Lowers refrigerant pressure, which quickly drops refrigerant temperature
Refrigerant is still in liquid form after leaving metering device
Mounted on high-pressure side of system, between dryer and firewal
Parttraine.
Refrigerant changes back to gaseous state in the evaporator, causing a cooling effect
Cabin air is cooled and dried as it blows across the evaporator
Only component mounted inside passenger compartment, behind dashboard
Path and characteristics of refrigerant
Low-temperature/low-pressure refrigerant enters the compressor (gas)
High-temperature/high-pressure refrigerant leaves the compressor (gas)
Refrigerant cools and converts to liquid in the condenser
Still under high pressure
Receiver/dryer removes water from refrigerant
Expansion valve reduces refrigerant pressure
Refrigerant converts back to gaseous state in the evaporator
Absorbs heat; when air blows across evaporator, it is cool and dry
