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Read the following to find out more about the air-conditioning system in your car and about what it can and does do. Your air-conditioning can do a lot more than keep your car at a pleasant temperature in the summer.
Did you know that the air-conditioning is responsible for keeping your windows clear in winter?
Windows fog up quickly when you get into your car and it is wet and cold outside and fogged-up windows significantly restrict your view. Fog is just humidity from the air that condenses on your windows. Humidity gets into your vehicle in clothing, shoes and coats.
But just turn a simple knob, and your air-conditioning can provide increased visibility and safety. It dries the air inside your car, which defogs the windows quickly.
Just switch on your air-conditioning and direct the air flow to your windscreen. Switch to air recirculation and set the blower and heater to maximum. You will then see the fog disappear from your windows.
But keep in mind that the automatic air-conditioning switches the system off automatically when the outside temperature falls below around +4 °C in some models from various manufacturers. Not all vehicles allow you to use recirculation mode when the air-conditioning is turned on and the air flow is directed onto the windscreen.
Your air-conditioning does not just change the temperature of the air inside your vehicle. It also ensures the air is clean!
Because the air-conditioning system also includes the cabin filter—and this performs the most difficult work: It filters dust, dirt and pollen from the air, up to 300 m3 of external air per hour. Thus, pollutants no longer reach the vehicle cabin. At such an output, it is easy to understand why the cabin filter is saturated after around one year and has to be replaced.
The evaporator is part of your air-conditioning system. It is located below the dashboard in a dark, damp area. This is the ideal location for bacteria, fungi and micro-organisms. These pathogens can then get into your vehicle cabin via the ventilation system. This can trigger allergic reactions in some people, such as sneezing, coughing and watery eyes. The problem can only be solved by disinfecting the evaporator during regular maintenance.
Did you know that your air-conditioning system can also contribute to your safety? Though it may not seem that obvious at first. Air-conditioning keeps the vehicle cabin comfortable and prevents blistering heat. When heat builds up in the vehicle, your body tires out more quickly, which in turn has a negative impact on reaction times and concentration. The risk of an accident significantly increases. Even at a temperature of 27°C in the vehicle cabin, the number of accidents in built-up areas increases by 11%. At an interior temperature of 32°C, this figure increases by about 22%*! But you can keep a cool head if your air-conditioning system is working properly and your reaction time and level of concentration levels are not impaired.
* These were the findings from studies by the Gesamthochschule Wuppertal [Wuppertal Comprehensive University] on behalf of the Bundesanstalt für Straßenwesen [German Federal Highway Research Institute].
There is a lot of material available about air-conditioning systems, compressors, cooling, etc. but people still frequently want to know how air-conditioning actually works. Why do I need a compressor and what does the cooling system have to do with my air conditioning system?
The following is a brief overview of how your air-conditioning system works. If you would like to know more or would like more details, please use our interactive and unique Know-how Tool to access more information. The link is on the right, or simply click here.
The individual components that make the refrigerant circuit of the A/C system are connected by hoses and tubes, forming a closed system. Driven by the compressor, the refrigerant circulates through the system. The gaseous refrigerant is compressed in the compressor, thereby increasing its temperature significantly. It is forced through the condenser under high pressure. The condenser removes heat from the strongly heated refrigerant using the air and the draft wind that flows through the attached condenser fan. This causes the refrigerant to condense, i.e. it changes state from gas to liquid. The filter dryer—the next station—removes contaminants and air from the refrigerant (now a liquid). This protects the components from damage caused by contaminants and ensures that the system is effective.
The refrigerant then continues from the filter dryer to the expansion valve. The valve can be compared to a dam. The valve maintains consistent pressure upstream from the dam, and the pressure then falls after the expansion valve when the volume increases downstream. Since the expansion valve is located just in front of the evaporator, the pressure of the refrigerant drops as it enters the evaporator. Evaporation—i.e. the change of state from liquid to gas—then causes evaporative cooling.
The evaporator is a heat exchanger, as is the condenser. It has an extremely large surface area, from which the cold from evaporation is dissipated to the surroundings. This dissipated cold is then blown into the vehicle cabin by the ventilation system where it provides a comfortable environment for the passengers. During evaporation, the refrigerant then changes state from liquid to gas and the pressure falls. This gas then continues its journey on the low-pressure side and the gaseous refrigerant travels back to the compressor.
Air-conditioning can be used throughout the year (for cooling in the summer and for warm dehumidified/dry air in winter).
To get dehumidified warm air, switch the air-conditioning on and set the heating regulator to “warm”. This provides pleasant, dry air in the vehicle - and fogged up windows clear very quickly. To speed up the process even further, direct the air to the windscreen and select the recirculated air function (some vehicle manufacturers, depending on the type of system, do not allow you to use the air recirculation mode when the air-conditioning system is turned on and the air flow is directed to the windscreen). Set the blower to maximum and turn off the air recirculation mode again after a short period of time. Some vehicle manufacturers switch off the air-conditioning automatically when the outside temperature falls below +4°C, depending on the system.
Do not be alarmed if, when parking in summer, you find little pools of water under the vehicle if the air-conditioning system has been running. This is normal and a direct result of using the air-conditioning system. It is condensation that forms on the surface of the evaporator and drains to the outside.
For more information on how to operate your air-conditioning and on its features, please refer to your vehicle’s operating manual.
On sunny days, park your car in the shade if possible. The interior temperature can rise to 60°C if your car is parked in the sun on a hot and sunny day.
Just a few small steps will provide a comfortable environment quickly:
Your air-conditioning system can be used 365 days of the year. For cooling in spring and summer:
To prevent fogged-up windows in fall and winter:
You should have your air-conditioning checked regularly to ensure it is in order. But why is it so important? And what does the garage actually do during an air-conditioning check and an air-conditioning service? How can it help to prevent a musty smell in the car? And why?
The two procedures are equivalent to a minor inspection (in the case of the air-conditioning check) and a major inspection (in the case of the air-conditioning service) of your car.
An air-conditioning check should be carried out once a year (or every 15,000 km) at your specialist garage.
Your air-conditioning system is thoroughly checked during the air-conditioning check. The cabin filterThe cabin filter keeps dust, dirt and pollen out of the vehicle cabin. However, it becomes dirty and, as a filter, its performance is therefore reduced. Cooling and heating performance is reduced and the windows may fog up (in fall and winter). After about one year or 15,000 kilometers, the filter has reached its capacity. It should therefore be replaced/cleaned once a year or every 15,000 kilometers. is replaced as well. All components of the system are reviewed (visually) and their functions and performance are checked. If necessary, your evaporatorEvaporative cooling takes place in your vehicle’s ventilation system via the evaporator. However, this also means that humidity develops at this point. Alternate cooling and heating in particular provides ideal conditions for bacteria, spores and fungi in the evaporator. These unpleasant passengers generally make themselves noticed for the first time as a moldy and unpleasant smell in your car. Besides the unpleasant smell, however, driver and passengers may suffer from sneezing and coughing, watery eyes and allergic reactions. That puts you, your health and your safety at risk. Only one thing helps to prevent such unwanted and annoying passengers—regular disinfection of the evaporator. is disinfected.
All of this promotes your health and safety!
Besides the air-conditioning check, there is the air-conditioning service. This should be carried out every two years. Your air-conditioning system is then put through its paces.
Of course, the garage carries out all steps of the air-conditioning check as well. Your cabin filterThe cabin filter keeps dust, dirt and pollen out of the vehicle cabin. However, it becomes dirty and, as a filter, its performance is therefore reduced. Cooling and heating performance is reduced and the windows may fog up (in fall and winter). After about one year or 15,000 kilometers, the filter has reached its capacity. It should therefore be replaced/cleaned once a year or every 15,000 kilometers. is replaced and all the air-conditioning components are tested to ensure they are functioning and performing correctly.
In addition, the filter dryerThe filter dryer is part of your vehicle’s air-conditioning system. As explained here, this component has two functions: it removes humidity from the air-conditioning system’s refrigerant and it acts as a filter. The component comes with a desiccant to keep the air-conditioning system dry, as humidity in the system can turn into acid, which can corrode and damage components and hoses. The filter function ensures that small particles of dirt and chips are filtered out of the system. These particles are created, for example, by wear of other components or damage in the system. To fulfil both tasks, a granulate filter cushion is installed inside the housing. However, this can only absorb a specific amount of humidity. The filter-dryer should therefore be replaced every two years, or if the air-conditioning system has been opened during repairs. and the refrigerantAir-conditioning systems are mechanical systems that cannot be 100% leak-proof. Some of the refrigerant may therefore evaporate from the system. This natural evaporation occurs in hoses and connection elements and can be up to 10% every year, which can lead to reduced performance. Your specialist garage checks the entire air-conditioning system is leak-proof so that leaks are discovered and prevented. You then always have the correct quantity of refrigerant in your system. In fact, the refrigerant has one more function. Oil is transferred through the system with the refrigerant, acting as a lubricant. The oil lubricates the various components. Only when, for example, the compressor is lubricated sufficiently does it function smoothly—in the truest meaning of the word. If lubrication is lacking, the components of the air-conditioning system may lose sealing and damage may occur. In particular, damage to the compressor, the heart of the system, can quickly lead to expensive repairs. are also replaced or filled up to the required amount. All components are naturally also checked for air-tightness so that the refrigerant stays where it belongs—in the air-conditioning system. Your evaporatorEvaporative cooling takes place in your vehicle’s ventilation system via the evaporator. However, this also means that humidity develops at this point. Alternate cooling and heating in particular provides ideal conditions for bacteria, spores and fungi in the evaporator. These unpleasant passengers generally make themselves noticed for the first time as a moldy and unpleasant smell in your car. Besides the unpleasant smell, however, driver and passengers may suffer from sneezing and coughing, watery eyes and allergic reactions. That puts you, your health and your safety at risk. Only one thing helps to prevent such unwanted and annoying passengers—regular disinfection of the evaporator. is also only disinfected during the air-conditioning service if necessary.
If there is not enough cooling or you think your system is not functioning properly or is leaking, please contact your specialist garage.
Only your specialist garage has specialists trained in how to handle the refrigerants, familiar with the highly complex systems and with access to the relevant tools.
However, there is one small step that every car owner with air-conditioning can take: Turn on your air-conditioning system for a few minutes at least once a week. This transports the refrigerant, and particularly the oil it carries, to all the components and lubricates them, preventing premature failures and damage.
And, of course, take your car in for an air-conditioning check once a year!
You can avoid components failing or being damaged by having the system serviced regularly. Subsequent repair is generally very expensive. For example, the filter dryer filters out humidity as well as particles of dirt and chips, which can damage the system if they are not removed. If the saturated filter dryer is not replaced, chips and particles can get into the air-conditioning system and damage other components.
Or the compressor—the heart of the air-conditioning system. It transports the refrigerant through the system. If your air-conditioning system is not serviced, the resultant lack of lubrication can lead to the accumulation of particles and chips which can damage the compressor. The cost of repairing a failed compressor is high, and may well leave you with a bill of up to 1000 euros or even more.
The evaporator is a heat exchanger, but is also the ideal breeding ground for bacteria, fungi and micro-organisms, as it is installed in a dark and humid environment.
Neglecting to disinfect the system creates a breeding ground for bacteria and micro-organisms. The blower and air jets then funnel the bacteria and micro-organisms into the vehicle cabin. Besides the unpleasant smell, driver and passengers may suffer from sneezing and coughing, watery eyes and allergic reactions. And this puts your health and safety at risk.
What are the parts of the cooling or air-conditioning circuit and how do they work? Experience all parts in action.