Basic air conditioning system function

Overview

This document contains information on:

 General

 Function requirement

 Versions

 Refrigerant

 Climate control function

 Maximum cooling

 Temperature control

 Maximum heating

General

The purpose of the air conditioning system is to bring the air in an area to a certain state and keep it there ("conditioning").

The basic air conditioning system functions are:

 To change air temperature (by heating or cooling)

 To change air humidity (dry)

 To remove air components (filtering)

 To change local air speed.

The climate control is regulated by the climate control control system.

Function requirement

 Circuit 30t ON

Refrigerant

Two different types of refrigerant are used:

 Synthetic refrigerant R134a

 Alternative synthetic refrigerant R1234yf

The refrigerant circuits for R134a and R1234yf are identical.

Climate control function

The outlet air temperature on the air vents is regulated using air mixing flaps. They continuously regulate the air flow of warm air from the heater core (4) and, where applicable, cooled air from the evaporator (3). The climate control control system uses the signals from the evaporator sensor and depending on the model involved, the signals from other temperature sensors to regulate the respective air vents.

The heater core is generally connected to the cooling circuit of the vehicle drive motor.

The evaporator is connected to the air conditioning system refrigerant circuit.

Maximum cooling
At maximum cooling request, the fresh air or recirculated air drawn in by the blower motor flows through the evaporator(3). It then flows, routed by the air mixing flap, past the heater core (4). The fresh air or recirculated air then flows unheated/cooled to the respective air vents.

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Temperature control
Depending on the temperature requested, the air mixing flaps open more or less, as required. As the temperature requirement increases, more and more fresh air or recirculated air flow from the evaporator(3) through the heater core(4). The temperature controlled fresh air or recirculated air then flows to the respective air vents.

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Maximum heating
At maximum heating request, the fresh air or recirculated air drawn in by the blower motor flows through the evaporator(3). It then flows, routed by the air mixing flap, completely through the heated heater core (4). The heated fresh air or recirculated air then flows to the respective air vents.

P83.30-5104-76