The concentration of pollutants inside the vehicle is four times higher than outside.
‘Rather sooner than later'
A principle that also applies when replacing a cabin air filter. Similarly to changing tyres, the rule of thumb ‘Easter to October’ or every 15,000 km can also be applied here.
Reason for changing the cabin air filter as often are the approx. 500,000 litres of air that modern vehicles channel into the interior every hour. Cabin air filters remove dirt particles, pollutants and germs and store them inside. However, even the best filter only has a limited absorption capacity, so changing it should be done sooner rather than later. Otherwise, it can only fulfil its tasks to a limited extent and even hinder the supply of fresh air - and thus very quickly reach a concentration as high as in 2001.
Good to know: If you are often commuting in areas with particularly high levels of air pollution - for example in large cities or areas with a dusty ground - shorter replacement intervals may be advisable.
What do I need to consider when replacing the filter?
- Identifying the location of the filter
You have read correctly. The location of the filter is not always the same. Some are located in the engine compartment near the windscreen wiper, some under the glove compartment or, as in the Ford Focus and Mondeo, very sneakily behind the gas pedal.
You can check where exactly the filter is located in your vehicle in the manufacturer's manual or research it online.
- Pay attention to the direction
In practice, experience shows that around one in three cabin air filters is installed in the wrong direction.
However, improper installation can lead to premature saturation or even failure of the filter! This is due to various reasons, one being the structure of multi-stage filters: a coarse stage made of paper initially filters out the largest particles such as dust or pollen from the incoming air before further, finer stages take over the filtration of bacteria, spores and other substances. By installing the filter in the wrong direction, the finer layers have to take on work that they are not designed for, resulting in premature saturation.
In addition, the way the filter is inserted into the holder also plays an important role. Incorrect installation can result in air bypassing the filter and thus entering the vehicle uncleaned.
Good to know: Many filters now feature a small arrow that indicates the direction of the air flow, which can be used as a guide.
What you should never rely on is how your previous filter was installed. It is best to start the engine and check by hand which direction the air is coming from. This will allow you to identify the direction of the air flow precisely.
- Clean the evaporator too!
When changing the filter, an important step often goes unnoticed: cleaning and disinfecting the evaporator of the air conditioning system. This is located behind the filter and therefore on the cleaned side of the airway. Not an issue if the evaporator is cleaned regularly. However, it becomes a problem if mould and bacteria form on the evaporator and thus release germs into the already filtered air.
To avoid this, the evaporator and the airway should always be disinfected when changing the filter.
To summarise, it can be said that a filter change may involve a few challenges, but it is still a worthwhile effort to get through the allergy season - and every other season - smoothly.
You can read about the different filters available and what to look out for in this blog post. Our entire range of filters can be discovered here.
