Automotive Air Conditioning Systems: Components and Functions

Automotive Air Conditioning System Components

The air conditioning system consists of the following primary components: compressor, condenser, filter drier, expansion valve, and evaporator.

The Compressor: Mission and Function

The compressor acts as a high-pressure, engine-driven pump. Its primary mission is to ensure the circulation of the refrigerant throughout the circuit by generating pressure and temperature differentials.

• Low Pressure: Receives the coolant in vapor form.
• High Pressure: Compresses the vapor and increases its temperature to push it through the system.

Compressor Types and Mechanics

Commonly used with R134a gas, compressors are categorized by their displacement mechanism:

• Fixed Displacement: Standard operation.
• Variable Displacement (Oscillating): Uses a disc to connect the drive shaft to five axial plungers. The angle of the disc determines the displacement and flow; a greater inclination results in higher output.

Sankyo and York Compressors: These units are designed for versatility, allowing for both horizontal and vertical mounting and rotation in either direction.

The Electromagnetic Clutch

The electromagnetic clutch maintains the connection between the engine and the compressor. When the coil is energized, it creates a magnetic field that attracts the disk to the pulley, engaging the compressor. If the system is not functioning, the compressor remains idle while the pulley spins freely on its bearing.

The Condenser: Heat Exchange

The condenser is a heat exchanger that dissipates heat from the refrigerant. It resembles an engine radiator and is typically constructed with copper tubing.

• Function: Converts refrigerant vapor into a liquid state.
• Location: Positioned in front of the radiator, utilizing airflow from vehicle movement or an electric cooling fan.

Filter Drier: Purpose and Maintenance

Located between the condenser and the expansion valve, the filter drier serves as a reservoir for liquid refrigerant and lubricating oil. It filters internal circuit particles and removes moisture, which is the primary cause of system breakdowns.