As any driver knows, the air that we breathe when driving on our highways and freeways is dirty, containing high levels of particulates like fine dust, soot from diesel trucks, and other pollution, which with pollen in the air is guaranteed to create problems for children with "young lungs", people with allergies, and other sensitive individuals. It may come as a surprise to many that the air inside your vehicle can be as much as six to ten times dirtier that the outside air!

Side by side of a dirty and clean cabin air filter

Enter the "cabin air filter", once only available in luxury vehicles. Many automobile manufactures have been quietly equipping their mainstream cars with them for several years from now. Amazing, most people do not know their vehicles are equipped with these filters (over 40 million vehicles have them), or are aware that they need periodic replacement to be affective, just like air filters you have on your heating air-conditioning systems at your home. These filters are designed to protect your health by filtering out pollution.

Cabin air filters are typically located on the passenger side of most vehicles, either under the dash or behind or on top of the glove box. You may have to look under the hood of some vehicles. Check your vehicle owner's manual for the location and method of changing your filter. If your vehicle owner's manual is not handy or it is missing, go to www.micronair.com and click on the "product" button for model by model installation information, or check with your service technician. For the do it person replacing your cabin filter is normally a simple job but some replacements require additional effort. The simplest method of purchasing a replacement filter is to your vehicle dealer; however, good aftermarket filters are also available and a trip to your auto parts store or a quick search on the web under "cabin air filters" may save you money.

There are two types of cabin air filters found on the market today; one is a particulate air filter that traps fine particulates and pollen in a pleated filter medium; the other adds an additional layer of activated charcoal to this particulate filter to help absorb toxic and foul smelling components.

Vehicle manufactures recommend changing your cabin air filter at least every year, or 10,000 to 15,000 miles depending on conditions for maximum performance. You may already have a restricted or plugged cabin air filter if you have noticed decrease in A/C performance, the interior of your vehicle fog up easily when you first run your A/C, or you notice strange smells coming from your A/C. Depending on the location of the air intake on your car it is possible for some filters to become damp or wet from the rain intake on your car it is possible for some filters to become damp or wet from the rain or from driving through standing water. A damp, dirty filter provides a good area for mold and bacteria to grow (by some accounts, especially in replacement filters made with cellulose). Change your filter and see if the smell goes away.

Finally, one trick to remember if you are noticing strange smells coming from your car's air conditioner, whether or not you have a cabin filter, is to switch off your A/C and run your fan on high for several minutes to get the moisture out of your system before you turn your car off. This may limit the funny smell some systems produce by removing the moisture that molds and bacteria need to grow in.

Also, there are other types of aftermarket car air filtering systems that go inside your vehicle. These may plug into your cigarette lighter for power, and state they use ionized air and other filter to remove particulates, smells, and pollution. We do not know how effective these are, and some similar home units are reputed to produce ozone (yes the same ozone we call smog) so be careful.