Cabin Air Filter
In most vehicles, the air intake for the ventilation system is located in the engine bay. This allows dirt, dust and other material from the road surface to be sucked into the intake. To prevent these contaminants from entering the cabin, most modern vehicles are fitted with a cabin air filter. This is different to the filter used for the engine air intake and is usually located just behind the glove box. Some of these filters can only remove particles but others can remove odors too. With a bit of work, a cabin air filter can also be retrofitted to an older vehicle.
The typical cabin air filter is about the size of a large book. It has a plastic frame that holds a filter element made of pleated paper or glass fiber. Some filters have an additional layer of baking soda or charcoal to remove odors. The charcoal ones are often called carbon-activated filters since charcoal is mostly carbon. A cabin air filter is an inexpensive accessory to replace and lasts for about a year in a vehicle that does mostly city driving. However, it will need to be replaced more frequently if the vehicle is used in dusty environments, such as rural areas that have many unsealed roads.
The first signs that the cabin air filter needs to be changed are reduced airflow and a musty odor coming from the vents. The color of the particle filter is often a good way of telling how much life it has left. A new particle filter is white but it slowly turn black as more particles become trapped inside it. However, it can be difficult to tell how much life the odor filter has left because it does not change color. Installing a new cabin air filter is a simple task that can be done by most people with a screwdriver.
In most vehicles, the cabin air filter is located behind or below the glove box. Some vehicle manufacturers put it inside the engine bay, making it more difficult to reach. Refer to the vehicle manual for the exact location of the filter and how to access it. If the glove box needs to be moved, there will often be a screw on the side that allows the box to swing down when removed. The screw may be hidden behind a plastic cover but that can be removed with a knife. The cover on the filter holder is usually attached with plastic tabs or screws. After the cover has been removed, the filter can be pulled out with minimal effort.
Before installing a new filter, check if there are any markings showing which end should be inserted first. Install the new filter into the holder and reattach the cover. Make sure the cover is properly locked in place, so that the filter does not vibrate and make a rattling noise when the vehicle is moving. If the glove box was moved to access the holder, swing it back up into place and insert the holding screw and cover. Filters that are made of plastic and pleated paper can often be recycled and should have markings on them indicating this.
Most new vehicles come with a cabin air filter as standard equipment, but there are also many vehicles that do not have one. The good news is that they can often be retrofitted with one. However, this is dependent on the location of the ventilation ducts and the amount of space available to install the large filter holder. Smaller cars have less free space available so there is less chance that a filter can be installed in one. Trucks and other large vehicles have more options because they generally have more space in the cabin and engine bay.
