SsangYong Rodius (2013 year). Service manual — part 180

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(2) Rear Air Conditioner Module

Roof air conditioner duct

Blower motor

Evaporator

Mixer door

Heater core

Air mixer door actuator

Rear floor

heater duct

Heater &

air conditioner

pipes

Wiring layout

Components

Rear mode actuator

Rear expansion valve

Rear blower motor

Heater valve

Rear blower resistance

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3. SYSTEM BLOCK DIAGRAM

A/C compressor OFF conditions

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Coolant temperature: over 115℃

Engine speed: over 4,500 rpm for more than 2 seconds

Engine speed: below 650 rpm

Maximum output due to abrupt acceleration

Excessive acceleration

Increased load during engine idling (to prevent the engine from shutting off)

Refrigerant pressure: over 32 bar or below 2 bar

Defects in A/C related system (refrigerant pressure sensor, coolant temperature sensor, cooling fan)

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4. A/C COOLING CYCLE

(1) System flow

"Compression -> Condensation -> Expansion -> Evaporation"

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(2) Functions

▶ Compressor

Condition: Gas

Function: Circulates the refrigerant and increases the pressure and temperature for easier

evaporation.

▶ Condenser

Condition: Gas/Liquid

Function: Cools and condenses the refrigerant by using ambient air to liquefy it under high

pressure.

Condition: Gas/Liquid

Function: Keeps the refrigerant free from moisture by separating/collecting the moisture from it.

▶ Receiver drier

▶ Expansion valve

Condition: Liquid/Liquefied gas

Function: Performs adiabatic expansion and flow control for easier evaporation.

1) Basic Operating Principle

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▶ Evaporator

Condition: Liquefied gas/Gas

Function: Cools the air by absorbing the heat from the air around the evaporator.

(3) Description for Each Cycle

▶ Compression

The evaporated refrigerant in the evaporator enters to the compressor. And the refrigerant gas is

compressed until it can be liquefied at ambient temperature.

Thus, the low refrigerant pressure is maintained so that the liquid refrigerant can be evaporated
actively at low temperature (around 0℃).

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▶ Condensation

The high pressure and high temperature gas (refrigerant) from the compressor is cooled down by

the fresh air entered into the condenser. Then, this gas is converted to liquid and collected in the

receiver drier.

The heat generated from the high pressure refrigerant is dissipated to the ambient air, and it is

called "heat of condensation".

The heat of condensation is the summation of the heat of vaporization (heat that the refrigerant

absorbs from the inside of the vehicle) and the calorific value converted from the amount of work

which is needed to compress.

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▶ Expansion

The liquid refrigerant lowers the pressure making its evaporation easily accomplished.

This process (lowering the pressure to the level at which evaporation easily takes place before the

liquid refrigerant is sent to the evaporator) is called

"Adiabatic Expansion".

During adiabatic expansion, the expansion valve lowers the pressure of the refrigerant and

determines the correct amount of refrigerant going into the air conditioning evaporator.

That is, the amount of heat, which is needed to stop the evaporation, is determined according to the

cooling load.

The expansion valve detects this and regulates the amount of the refrigerant exactly.

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▶ Evaporator

The refrigerant is converted from liquid to gas in the evaporator.

(The refrigerant in the form of fog in the evaporator is vaporized actively)

At this time the refrigerant, in the form of liquid, absorbs the heat in the air which is need for

evaporation (latent heat) and is cooled down. Then the blower blows the cooled air inside the

vehicle to lower the temperature.

There are liquid refrigerant from the expansion valve and evaporated refrigerant in the evaporator.

The evaporation temperature can be predicted from the evaporation pressure (i.e. relationship

between saturation pressure and saturation temperature).

It is important to keep the pressure inside the evaporator low, so that the refrigerant is evaporated at

low temperature to make sure the completely evaporated refrigerant is entered into the

compressor.

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