Climate control system

Battery

Filters

Windscreen wipers

Shock absorbers and suspension

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Bulb

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Bodywork

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Radiator and thermal system

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Timing system

Spark plug

Clutch

What is it?

Nowadays, climate control is no longer considered as optional or luxury, but as standard vehicle equipment, and over 80% of vehicles on the road are fitted with it.

An increase in glazed surface and longer journey times are some of the reasons why climate control is now more important than ever before in terms of on-board comfort. In winter it assists with rapid demisting, controlling the humidity level in the passenger compartment to improve visibility and driving safety. Thanks to the passenger compartment filters, even the quality of the air generated in the passenger compartment is now better than ever before.

air-conditioning_image

The climate control is a closed system, which acts upon differences in pressure and the change in state which the coolant gas undergoes throughout the circuit.
There are many components involved:

  • The compressor aspirates and compresses the coolant, modifying its state and temperature (from low pressure and low temperature to high pressure and high temperature)
  • The condenser transfers heat to the outside air and condenses the coolant, which then changes from a gas to a liquid
  • The coolant passes through the drier filter, which absorbs humidity and removes impurities
  • It then reaches the expansion valve, where it undergoes a drastic fall in pressure and temperature
  • In the evaporator, the coolant changes state again, from a liquid to a gas. This absorbs heat and lowers the temperature of the air generated in the passenger compartment through the air vents

Once the cycle is complete, the coolant is once again aspirated by the compressor. All of the components are connected by rigid piping.

The climate control system is also supported by two motor-driven fans: one radiator fan assembly and one passenger compartment fan assembly.

Before entering the vehicle via the air vents, the air passes through the passenger compartment filter which removes polluting particles and, in the case of active carbon filters, also harmful gases and unpleasant odours.

CompressorDiscover

CondenserDiscover

DRIER FILTERDiscover

Expansion valveDiscover

EvaporatorDiscover

Did you know?

Air conditioning or climate control?

Air conditioning or climate control?

Air conditioning is a device which is only capable of cooling, while climate control can both cool and heat the air. Air conditioning uses the characteristics of gases, which heat up or cool down when submitted to different pressures and physical stresses. There are different types available, depending on the operating mode:

  • Manual: all adjustments are the responsibility of the user
  • Semi-automatic: where the automatic adjustment is restricted to the temperature and ventilation speed
  • Automatic: where the flow, temperature and ventilation speed are all managed by a control unit

Depending on the number of zones which can be individually adjusted, there is a single zone, dual zone, triple zone and four zone climate control systems available.

Equivalent temperature
 

Equivalent temperature <br /> 

If a fan is switched on in a room, the moving air has the same temperature as the still air, but when it reaches you it seems cooler. On top of a mountain, where the air is zero degrees, in the sun it is easy to feel warm. Regardless of the temperature recorded by the thermometer, humidity makes us feel colder at lower temperatures and warmer at higher temperatures. The thermal comfort we perceive is not just a question of a measurement on a thermometer. The most sophisticated climate control systems operate according to equivalent temperature, or the complex management of the climate based on perceived thermal comfort, to ensure the passenger compartment occupants enjoy their required temperature. They operate using algorithms, which make the climate control system function according to various factors detected by dedicated sensors, which allow the system to anticipate and compensate for climatic changes inside and outside the passenger compartment.

Leak detector for malfunctions

Leak detector for malfunctions

One of the most common causes of functional anomalies in climate control systems is inefficient cooling circuit flow, which very slightly reduces the quantity of coolant gas, leading to a gradual reduction in performance through to a total breakdown. In these cases, careful leak detection must be performed on all of the system's components.

There are various types of leak detection options: contrast solutions to be added to the coolant fluid, and UV lamps which make the contrast solution visible; electronic detectors which give off an acoustic signal when a leak is detected, however small, and including in hard to reach areas; solutions which, when sprayed in liquid form at the point where the flow is reduced, form a foam which reacts with the coolant gas. Finally, there is leak detection using nitrogen, a useful technique both when flushing the system and when checking flow, performed using special climate control flushing kits.

FIAT’s tips

To ensure your climate control system always runs efficiently, you should use it often, even in winter. The climate control is a system in itself, with its own motor (the compressor), heat exchangers (condenser and evaporator), filters and tubes, and it is always under pressure, even when it is not activated.
In every season, the system plays its part in improving on-board safety: by dehumidifying the air which enters the passenger compartment, it solves the problem of window misting, which can be especially irritating in autumn and winter.
At the end of a long journey, especially on rainy and damp days, it is a good habit to get into to leave the air vents running on full power for a few minutes before stopping. Simply switch off the climate control system and leave only the ventilation active. This will allow the evaporator and the vents to dry and passengers can get used to the external temperature. It also limits the formation of mould and bacteria caused by damp, which can lead to unpleasant odours and allergic reactions. Regular replacement of the passenger compartment filter is crucial to ensure you always have clean air on-board.

For optimum thermal comfort and to avoid thermal shocks, especially in summer, the climate control should never be programmed at too low a temperature. Ideally, the difference between the ambient temperature and the in-car temperature should be no more than 6° – 7°.
Direct the cool air flow upwards and not directly on to the body. This helps the heavier cool air to mix with the lighter warm air.

To ensure optimum climate control performance, it is good to recharge the coolant gas every two years.

air-conditioning_image

Self-diagnosis

If you notice a reduction in the performance of your climate control system and it doesn't seem to be cooling efficiently, you may need to carry out leak detection and recharge the coolant gas. In any case, it is recommended that you recharge the gas every two years.
If you notice a pool of water forming underneath the front of your vehicle after travelling with the air conditioning switched on, this is not a problem: it is the evaporator dripping because the frost which forms on the panels is melting.

If your windows are often misted, even when the climate control is on, the passenger compartment air flow may be low. If the passenger compartment filter is too full of impurities or clogged for a prolonged period, it must be replaced.