Cabin air filters have an increasingly important role to play both due to increasing levels of air pollution and the steadily rising number of people with respiratory diseases and allergies. However, knowledge of these filters remains low, with few drivers and in some cases technicians aware of which type of cabin filter is best for particular needs. 

To combat this issue, German parts specialist MEYLE has provided some straight forward advice. 

Standard particle filters are designed to filter air pollutants in various states and sizes of less than 5 micrometres. These include pollen, road dust, brakes dust, tyres degradation, soot and dust. 

An activated carbon filter offers the normal function of a standard filter but is also capable of binding gases such as ozone, nitrogen or sulphur dioxide. The wide surface area of the activated carbon is what makes this possible.

However, as MEYLE point out, the surface structure and effectiveness of activated carbon depends on its origin. Coconut fibre, for example, has a rather broad surface structure compared to stone, lignite and charcoal. This is particularly advantageous as it allows a longer contact time with the coal while a higher amount of iodine in mg/g coal, also known as the CTC value, can be absorbed. 

A longer contact time also ensures that more organic compounds can be absorbed, allowing the filter to work more effectively. 

However, even the highest quality raw materials are of limited use if the manufacturing process is not carried out properly, since even a small bypass will result in a large proportion of the filter performance being lost. An elastic fleece makes for the ideal material in this case, as it not only ensures that the filter can adjust optimally to the space provided for it in the vehicle, but also that the filter performance remains consistent over time. 

In addition to particle filters and standard activated carbon filters, there are others that filter not only pollen, fine dust and gases, but also nitrogen oxides (NOx). The unique aspect of this is that NOx is not only filtered, but also bound as a chemical salt compound which is not released even when disposed of. This is made possible by an additional layer of specially impregnated activated carbon.

MEYLE says filter development has progressed rapidly over the past couple of years and will continue to do so in the future. The first HEPA filters, which filter viruses as well as fine dust and bacteria, are already on the market and the trend is growing.

MEYLE offers a comprehensive range of cabin air filter specifications for a huge range of vehicles. This includes particle, activated carbon, biofunctional and MEYLE PD cabin air filters to meet all requirements. These are available from MEYLE stockist.