Move safely through the traffic with a clear head!

Did you know that your air conditioning system can lose up to 10 percent of its refrigerant every year? This not only reduces cooling capacity, but can, in the worst case, cause damage to individual components—and even lead to total failure of the system! Regular maintenance of the air conditioning system helps to ensure that it continues to function smoothly.

An air conditioning check and service can save you money, as any damage can be detected in good time before it causes total failure.

Air conditioning checks and services keep you safe, maintaining a comfortable temperature and allowing you to concentrate fully on the road.

Air conditioning checks and services protect your health, keeping dust, pollen, fungi, and bacteria out of the vehicle interior.

A regularly serviced, properly functioning air conditioning system is also essential for cooling the temperature-sensitive traction battery in electric and hybrid vehicles. Additionally, it extends the traction battery’s service life and improves the vehicle’s cruising range.

A/C checks are especially important for electric and hybrid vehicles!

For electric and hybrid vehicles, regular maintenance of the air conditioning system plays an even more important role, because—as well as cooling the interior—it often helps to cool the battery. To function optimally, the battery must be operated within a specific temperature spectrum—even before starting! A properly functioning air conditioning system thus has a positive impact on the reliability and cruising range of the vehicle and on the service life of the temperature-sensitive battery.

Putting health and safety first!

Two issues take center stage in an air conditioning check: health and safety! Scientific studies have shown that our ability to concentrate decreases as temperatures rise, and we tire more quickly. At the same time, our reaction time slows. This significantly increases our risk of having an accident. Vehicle air conditioning systems cool the cabin to a pleasant temperature while dehumidifying the air. This means that the driver’s ability to react and concentrate is maintained over a longer period of time.

Condensation builds up in the inaccessible, dark, and dank environment between the fins of the evaporator—a breeding ground for bacteria and fungi. That’s why the evaporator is disinfected during an air conditioning check.

An air conditioning check therefore always includes regular replacement of the cabin filter, which filters dust, pollen, and dirt particles out of the air before they can reach you in the vehicle interior. This improves the air quality and increases safety, as you’re less likely to sneeze while you’re driving!

The filter-drier removes dirt particles from the refrigerant and absorbs moisture. But since its capacity is limited, precautionary replacement of the filter-drier is recommended in older vehicles and/or vehicles with high mileage in order to protect the air conditioning system against damage caused by humidity.

CareMetix® turns your car into your sanctuary

When you’re on the road, you need clean air to focus and drive safely—and to feel good. But the air we breathe is often polluted with harmful, allergenic substances and odors that conventional filters can’t eliminate. The solution: CareMetix®, a world first with S5 broadband technology—5 layers provide 5-fold protection.
Find out more at:

How often should I take my car for an A/C check or service?

Set aside a little time for air conditioning maintenance and have your A/C system checked and serviced regularly by a specialist workshop. The following intervals are typical:

Air conditioning check (once a year or every 15,000 km)

  • Replacement of the cabin filter
  • Visual inspection of all components
  • Function and performance test
  • Disinfection of evaporator, where necessary

Air conditioning service (every two years)

  • Perform all services included in the air conditioning check (see above)
  • Replace the filter-drier, where necessary
  • Change the refrigerant
  • Check leaktightness
  • Disinfect the evaporator, where necessary

At a glance: A/C check flyer

Our flyer about air conditioning checks summarizes everything you need to know about them—and what happens if an air conditioning system isn’t checked regularly.

Download [PDF; 390 KB]

Ole the Penguin explains the importance of regular air conditioning checks

Video is loading

How often should I take my car for an A/C check or service?

Design of an air conditioning system in a combustion engine

Automotive air conditioning systems work like domestic fridges. In both cases, a compressor pumps refrigerant through a closed system. This extracts heat from the cabin (or fridge) and conducts it outwards.

However, while a fridge has an electrically driven compressor, an automotive air conditioning system is driven mechanically via a V-belt or ribbed belt (except in electric and hybrid vehicles). The individual components in a fridge’s cooling system are close together and usually linked by means of copper pipes with only a few connecting elements with the potential to become loose.

The lines in a vehicle are much longer, and flexible hose lines are used for design reasons. There are many more connecting elements. Very little refrigerant is lost from fridges because they remain in one place, the operating conditions (ambient temperature, air humidity, on and off phases) rarely change, and metal piping is used. Owing to the pipe material and the few connecting elements, very little moisture penetrates into the system. That’s why it’s maintenance-free—unlike an automotive air conditioning system.

Detailed insights into how air conditioning systems work in vehicles with combustion engines can be found in our TechTool.

How A/C systems work in electric vehicles

Though the thermal management of combustion engines and electric drives is technically similar, it’s more complex in electric drives. The traction battery, electric motor, and power electronics have different temperature requirements, which must be strictly adhered to. To achieve this, several cooling and refrigerant circuits are required. Optimum temperature control impacts both the service life of these components and the cruising range of electric vehicles. So, in addition to air-conditioning the cabin, the air conditioning system also helps to cool the components crucial to electric drives. It’s clear: a properly functioning and serviced air conditioning system is extremely important!

The more powerful the batteries are, the more complex the coolant- and refrigerant-based circuits need to be. The entire cooling system is subdivided into several circuits, each with its own low-temperature radiator, coolant pump, thermostat, and coolant shut-off valve. The refrigerant circuit for the air conditioning system is integrated via a special heat exchanger (chiller).

The coolant temperature for the electric motor and the power electronics is maintained at below 60°C inside a separate circuit (inner circuit on the figure) using a low-temperature radiator. To achieve maximum performance and ensure the longest possible service life, the battery’s coolant temperature must be kept between approximately 15°C and 35°C at all times.

When temperatures become too low, the coolant is heated via an auxiliary high-voltage heater. When the temperature gets too high, it’s cooled via a low-temperature radiator. If it’s still too hot, the chiller reduces the coolant temperature further. The refrigerant in the air conditioning system flows through the chiller and further cools down the coolant, which also flows through the chiller (indirect battery cooling via the air conditioning system). Everything is controlled with the aid of individual thermostats, sensors, pumps, and valves.

Cooling the battery during fast charging is another important function. Electric vehicles have a charging loss of about 10 percent. Charging losses generate heat in the battery, which has to be dissipated by the cooling system. Since there’s no airstream when charging, the air conditioning compressor is designed to provide the necessary power.

Detailed insights into how air conditioning systems work in electric vehicles can be found in our TechTool.

OzonePRO—for clean and healthy air in vehicles!

Are your blowers pumping out poor-quality air? Unpleasant odors? It doesn’t have to be that way! OzonePRO from MAHLE is a professional cleaning system that puts an end to polluted air. Ozone treatment is a natural way of cleaning areas contaminated with bacteria, viruses, spores, mold, and mites. It’s safe and 100 percent environmentally friendly!

Ask your specialist workshop to use OzonePRO from MAHLE to treat your vehicle—you’ll be delighted with the results.