Air Conditioning System — Basics and Precautions (Mercedes-Benz C-Class W201)

Air conditioning is fitted as standard on later high-spec models and optional on some lower-spec models. In combination with the heater, the system allows the cabin to be kept at any desired temperature. It also reduces the humidity of the incoming air to prevent the windows from misting up when cooling is not required. The air conditioning system's cooling circuit acts like a conventional domestic refrigerator. The compressor, which is belt-driven by the crankshaft pulley, draws in refrigerant in its gaseous state. When compressed, the refrigerant heats up, but passes through the condenser (located in front of the engine radiator) it loses temperature and becomes liquid. After dehydration, the refrigerant passes through the evaporator (installed along the heater/ventilation unit), where it expands and turns into a gaseous state. This transition from one state to another is accompanied by the absorption of heat and cools the air passing through the evaporator. The cooled air mixes with the warm air from the heater and thus achieves the desired temperature of the air entering the cabin. The refrigerant again enters the compressor, and the cycle is repeated.

The system is equipped with various sensors and controls to ensure that it does not go beyond its operating modes. Additionally, when the system is turned on, the idle speed increases to compensate for the additional load on the engine required to operate the compressor. An electronic sensor monitors the difference in engine and compressor speeds so that when the difference increases and the compressor fails, the compressor clutch is disconnected and the drive belt is protected.



Although the refrigerant itself is not toxic, in the presence of an open flame (or a lit cigarette) it forms a highly toxic gas.

Do not heat refrigerant lines above 110°C, such as when welding or drying paint.

Do not operate the air conditioning system if you know it is low on refrigerant, as this may cause the system to malfunction.

Note: The electronic air conditioning control system can only be checked with special equipment. For this reason, any questions regarding incorrect operation of the air conditioning system should be addressed to a Mercedes-Benz service station. A description of how to check the refrigerant level is given in Chapter 1.

Article borrowed from the web portal: mercedesman.ru

Warning: The refrigerant in the system is under high pressure. The refrigerant is potentially dangerous and should only be handled by trained personnel. Refrigerant in contact with skin can cause frostbite. In the presence of an open flame, the refrigerant forms a highly toxic gas. Uncontrolled release of refrigerant from the system is dangerous and harmful to the environment. For these reasons, disconnecting any part of the system without specialized training and equipment is not recommended.