Short car journeys are seriously damaging to the health of drivers and passengers, especially if the vehicle cabin air filter is clogged and dirty. That is the message from parts specialist DENSO which says that new research shows in-car pollutants are reaching dangerous levels.

DENSO says without a properly functioning cabin filter the air inside a car could be up to eight times dirtier than the outside, especially during the first few minutes of switching the engine on. The company says its combination filters are among the most effective on the market, using high-quality, non-woven fabric enhanced by an added layer of activated charcoal. The charcoal creates an effective ‘adsorption’ process that condenses gases on the surface, eliminating unpleasant and harmful fumes and odours.

The Combination filter is extremely precise, blocking particles that are 1,000 smaller than a human hair and are capable of removing up to 25% more major pollutants from the air than standard Particle Filters which don’t contain the activated carbon media.

DENSO also points out that older filters which are clogged or dirty can harbour mildews and bacteria, which can cause allergies and discomfort to car passengers. Aside from poorer filtration, a blocked filter can also make window defogging more difficult as particles will remain airborne for longer and there will be less air flow from fan outlets. A poorer quality cabin air filter also poses the risk of compromising a vehicle’s HVAC system completely by causing an increase in the pressure drop, resulting in costly damage.

To keep the filter working in optimum condition, DENSO advises workshops to check air filters regularly, and the OE supplier recommends replacing cabin filters at least once a year or after 10,000-15,000kms.