Detailed Pollen Filter Information

Background to Pollen Filters 

Pollen filters and Cabin filters are practically the same thing, however they do have a different function. When people refer to pollen filters they normally mean a filter that cleans air coming into the car. Cabin filters on the other hand are taken to mean filters that treat the incoming air and the recirculated air. In this website we refer to both terms in a generic sense, and any reference to one, means both types. Cars will generally have either a pollen filter or a cabin filter, rather than both.

Mainland Europe has lead the way with pollen filters for cars and vans. Pollen filters have been widely fitted to new cars built in Germany since about 1989. Since then other car manufacturing countries in the rest of Europe and the Far East, have mostly followed suit. Now the vast majority of new cars sold in Europe have pollen filters fitted as standard. Incidence of pollen filters fitted to American cars is lower than Europe, presumably because their population and therefore pollutants are spread far more thinly than is the case in Europe.

Although originally fitted to protect the air conditioning systems from dust accumulation and the resulting smells and loss of efficiency that the dust can cause, the benefits that pollen filters gave to car occupants was soon realised. Pollen  filters were then fitted to cars and vans with and without air conditioning and added to the ever-increasing list of sales attributes of the new models.

Technically pollen air filters are quite straightforward. Many originals ones used heat bonded non-woven synthetic fibres and were cased in moulded plastic frames. The media was usually pleated in order to maximise the area of media available to the airflow, which prolongs pollen filter performance and its life.

Most modern pollen filters have dispensed with the plastic frame and use instead a ‘melt blown’ synthetic card frame, and melt blown synthetic media. These type of filters rely much more on the filter housing when installed, for their structural integrity, compared to the old plastic framed variants, which were very strong in their own right. Some of the prestigious brands new cars have pollen filters with activated carbon, enabling them to capture smells, nuisance and toxic gases, as well as the particles. Puravent typically supply pollen filters with carbon.  We do also for some applications offer a choice between a standard and a upgrade pollen filter.

Pollen filter Change Frequency

Most car manufacturers recommend changing pollen filters at each service interval or every second interval if it is a particularly short distance between services. Whether garages actually change these filters in accordance with the manufacturer’s recommendation, is something that only the drivers can ask and check. Our recommendation is that in predominantly open road driving then change every 15000 miles, if predominantly city driving and heavy traffic, change at least every 10000 miles.

Puravent Upgrade Pollen Filter Design

All Puravent upgrade pollen filters are made from a number of filter layers. These layers are bonded together and pleated to maximise the filter area in the pollen filter. A. Prefilter This is the first layer of the pollen filter that the air meets and it is where the largest particles are captured. The prefilter layer fibres are electrostatically charged which attracts dust particles. As large particles accumulate on the media the filtration efficiency of the layer increases as the particles themselves act as a filter to other particles. In this layer the captured dust will be predominantly road dust and pollen. B. Secondary This layer again consists of electrostatically charged fibre, but fibres are far finer and more densely packed compared with the prefilter. It is in this layer that the very fine particles will be trapped, such as soot and the finer particles of road dust otherwise destined for your lungs.

Click on picture above to enlarge

C. Carbon The activated carbon layer of the pollen filter comprises of tiny granules of porous activated carbon. There is far greater carbon surface within the microscopic pores of activated carbon than on the outside of the granule. Unbelievable as it may sound,  in a teaspoon of activated carbon granules there will be a surface area equivalent to a football pitch. It is this surface area that is critical in filtering pollutant gas molecules from air. Pollutant gas molecules are attracted into the pores of the carbon and onto the carbon surface by what are known as Van der Walls forces. This is otherwise known as physical adsorption.

	The carbon granules in a Puravent pollen filter make all the difference and mean the filter not only captures dust but also captures fumes. The carbon granules are tiny and each smaller than the nib of a ball point pen.

D. Strength layer There is a layer on the back of the pollen filter media which is made of course synthetic fibres. This layer does not have any filtering properties, but adds some strength to the other layers ensuring that, in use, the filter does not physically fail.

Standard pollen filters that can be bought from other suppliers do not have an activated carbon layer to catch pollutant gases. Indeed they may not even have a properly graduated structured media with prefilter layer and secondary filter layers. Some suppliers pollen filters are not even pleated.

Puravent upgrade pollen filters are technically superior to standard filters and designed specifically to fit your car make and model. New Puravent  pollen filters will trap, as close as matters, 100% of particles of 3 micron and larger size, and 80% of particles that are 0.3 microns size (1 micron = 1000^th of a millimetre).

Not using a Pollen Filter  - The Health Risks 

With concentrations of some pollutants being easily up to 6 times the level on a congested road compared to the level measured at the pavement of the same road, it is no surprise that people in cars are prone to suffer from asthma, allergies, hay fever, headaches and nausea when driving in heavy traffic.  Not only that but consider some other research findings;

Pollen Filters  - Did you know ?

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