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HVAC - Description & Operation (Xc): Overview Volvo V70 II

Automatic HVAC System 2 illustrations ~316 words

Scheme 1177

Scheme 1177: Introduction

There are five main components in the climate control system

  1. evaporator
  2. receiver drier
  3. compressor
  4. condenser
  5. expansion valve.

The system is filled with a suitable quantity of refrigerant and oil. The role of the oil is to lubricate and seal the compressor (piston and cylinder).

A fluorescent leak-tracing agent is added to the refrigerant. The leak-tracing agent makes it possible to trace leaks using UV light.

Scheme 1178

Scheme 1178: Principle sketch of climate control system

Included in the climate control system

  1. Compressor
  2. Condenser
  3. Engine cooling fan (the same cooling fan used by the engine cooling system)
  4. Receiver drier
  5. Expansion valve
  6. Evaporator
  7. Blower fan.

Explanation

A - High pressure, warm fluid

B - Low pressure, cold fluid

C - Low pressure, cold gas

D - High pressure, warm gas

Dark arrow - Warm air

Light arrow - Cold air

The system is divided into

  1. a low pressure side (B, C)
  2. a high pressure side (A, D).

The two sides are separated by the compressor (1) and the expansion valve (5). The evaporator (6) is located on the low pressure side and the condenser (2) is on the high pressure side.

The design of the climate control system in a vehicle is based on the laws of nature, which mean that liquids evaporate when they are subjected to a temperature increase or a reduction in pressure and that heat is absorbed during this process.

If the hot vapor is then cooled again, the heat that has been absorbed is released and the gas reverts to liquid form. This process is repeated as many times as necessary, so that "cooling is produced" continually. This is the same type of process as used in refrigerators, for example.

General information about reading off status of buttons on dashboard environment panel

The result from reading off the status for buttons on the dashboard environment panel in order from left to right.