Imagine you’re cruising down the highway, enjoying the cool breeze from your air conditioner when suddenly, a funky smell hits your nostrils and you’re not near a dairy farm. Oof! It’s probably your cabin air filter (also known as an AC filter).
Cabin air filters are responsible for maintaining good air quality inside your vehicle. They trap dust, debris, bacteria, pollen, and even foul odors. Over time, these filters get dirty and clogged, which affects the airflow in your vehicle and the overall comfort inside.
While replacing the filter is the most common solution, cleaning it instead is often all that’s needed to stop unpleasant smells and weak airflow.
See Also: 5 Symptoms of a Bad Air Filter
Signs of a Dirty Cabin Air Filter
When your cabin air filter gets dirty, it can cause a range of issues in your vehicle. Keep an eye out for these signs to know when it’s time to give your filter a good cleaning or consider a replacement:
1) Unpleasant Odor
If you start noticing a bad smell, such as a gym locker or sweaty socks, coming from your vents, it’s likely that your cabin air filter needs attention. Contaminants trapped in the filter can lead to a musty or moldy smell, which gets stronger as you increase the airflow.
2) Reduced Airflow
When your A/C filter becomes clogged with debris, it obstructs the flow of air through your ventilation system. You’ll notice your vents providing less air than usual, even when you crank up the fan.
3) Dust and Debris
Finding extra dust or debris on your dashboard and seats, even after cleaning your car, is a warning sign that your cabin air filter isn’t doing its job. When it’s dirty or clogged, the filter isn’t able to prevent contaminants from entering your cabin.
4) Windows Fogging Up
If your windows and windshield start fogging up more frequently than usual, it could be due to temperature and humidity differences between inside and outside air. This is often a result of a dirty cabin filter, which doesn’t efficiently remove moisture from the air.
5) Whistling Noise From Vents
A whistling sound coming from your vents is another indication that your cabin air filter may be clogged or damaged. Air struggling to pass through the filter is the cause of this unusual noise.
Locating the Cabin Filter
If you’ve never heard of a cabin air filter it’s probably because it’s generally hidden out of sight, and the specific location varies depending on the manufacturer and model of your vehicle. However, there are a few common places to find them:
- Behind the glove box: This is by far the most common location for this filter. To access it, you might need to remove a small panel from the back of the glove box, or sometimes the whole glove box flops down and out of the way.
- Under the dashboard: In some vehicles, the cabin air filter might be located under the dashboard on the passenger side. You might need to remove a kick panel or other trim piece to access it.
- Under the hood: In rare cases, these filters can be found under the hood near the windshield on the passenger side. This is more typical of older vehicles or European cars, so be sure to consult your owner’s manual to confirm the location if you’re not sure.
Before searching for the cabin air filter, it’s a good idea to familiarize yourself with what the filter looks like. Generally, it’s housed in a plastic container, shelf, or bracket and if your vehicle was made after the year 2000, then your cabin filter should be located in one of these common locations.
Don’t hesitate to consult your vehicle’s owner’s manual for details about the specific location of your cabin filter or even the exact steps you’ll need to take.
Cleaning a Cabin Air Filter
Most quick lube establishments will recommend that you replace your cabin filter if it looks just a little bit clogged or dirty. What you need to understand is that filters do not get completely clogged right away.
It is a gradual process where the filter slowly gets clogged while less air is able to pass through. During this process, you can simply clean the filter instead of replacing it entirely. If you do this, then you can wait for 15,000 miles before replacing the filter.
Below are the steps for cleaning a car air conditioner filter.
1) Find the Filter
If you own a vehicle that was made after the year 2000, then your cabin filter should be located behind the glove box or in the driver’s foot well. It will be easy to recognize because it is housed in some sort of container, shelf, or bracket.
To open the container, there will be either clamps or a wing nut that you’ll need to remove. Once you do, the container can easily be taken off and the filter will be revealed underneath it.
If you still have trouble finding the filter, check your owner’s manual or look online to find a chart of where the cabin air filter is on your particular model vehicle.
2) Remove the Filter
After the cabin air filter is revealed, you just need to pull it out. There are no additional nuts or clamps holding the filter down. The canister was the only part that held the filter. Take the filter and place it down somewhere safe.
3) Clean the Filter
There are two ways you can clean the filter. You can either use a vacuum cleaner or you can use a bucket of soapy water. If you’re using the latter, you just put the filter into the soapy liquid and move it around in there until it is soaked thoroughly.
After a few minutes, take the filter out and shake it to get the extra soapy water out that remains.
Use clean water to gently rinse from the clean side out to allow the dirt and debris to flow out of the filter. Leave the filter on a towel so that it can dry off. It may take several hours for this to happen.
If you’re using a vacuum cleaner, you just need to vacuum one side of the filter with it for one minute and then do the same on the other side.
4) Reverse the Process
Once your cabin air filter is fully dry, you can reinstall it in your vehicle. Be sure to position it correctly, with the dirtier side facing away from your vehicle’s HVAC system. Gently slide the filter back into its housing and secure any clips or fasteners.
Types of Cabin Air Filters
1) Paper Air Filter
Paper cabin air filters are the standard type of HVAC filters. These are the filters that come in most vehicles. They are usually made out of multifiber cotton like an engine air filter and layered to keep particulates out of the passenger space.
2) Reusable Air Filter
Reusable cabin air filters are made of rubber or polyurethane around the edges to seal against the HVAC system. The filtration material is made of a washable fabric surrounded by an aluminum support structure that doesn’t degrade over time. These filters are often odor resistant, keeping your interior smelling fresh.
Here is an example of a cabin air filter that fits many Japanese cars such as Toyota, Subaru, Lexus, and Scion.
This cabin air filter is compatible with many American trucks such as Chevy, GMC, and Cadillac.
3) HEPA Filter
HEPA stands for High-Efficiency Particulate Air filter. In order to meet the HEPA standard in America, the filter must remove at least 99.97% of particulates from the air that passes through it.
A HEPA filter is adept at filtering smoke, dust, allergens, soot, and many other contaminants that are unhealthy to breathe for a prolonged period of time. Not all cabin air filters are HEPA filters. HEPA filters typically cost more, but are well worth it.
Can All Cabin Air Filters Be Cleaned?
Some cabin air filter are made of paper and should be replaced instead of cleaned. Reusable filters can be cleaned using a vacuum, a hose, or a microfiber towel and a bucket.
Cabin Air Filter Replacement Cost
The cost to replace a cabin air filter depends on whether you’re having it professionally done or not. If you are having a quick lube place, auto repair shop or dealership replace it, then it will cost you anywhere from $30 to $100 to replace it.
A cabin air filter itself will only be between $10 to $20 in most cases, but the labor costs will be between $20 and $60. You’d be better off replacing it yourself because it is not that hard for anyone to do.
How Often Should a Cabin Air Filter Be Changed?
Typically, it’s recommended to replace your cabin air filter every 15,000 to 25,000 miles or once a year, whichever comes first. However, it’s best to consult your vehicle’s owner manual for the manufacturer’s recommendation.
Keep in mind that if you frequently drive in dusty or polluted environments, you may need to change your filter more often.