Pureflow Air Filter Product FAQ

Have a question about your PUREFLOW air filter, or about air filters in general? We have all the answers you’re looking for for your cabin air filter replacement. Whether you’re wondering what a cabin air filter does, how a cabin air filter works, which cabin air filter is best for your car, or how to install your cabin air filter, you have come to the right place.

Whether you’re trying to install your first cabin air filter and have no idea what to do or how to do it, or you’re an old hand at anything mechanical and just need to look up the correct part number for your vehicle, PUREFLOW air filters are the site for everything on the subject and can help the novice and the expert alike.

What is a cabin air filter?

Cabin air filter purifies the air we breathe inside the car. Just like the AC filter at home, cabin filters are a pleated filter with various shapes and sizes for different cars and models. Most new cars are equipped with a cabin filter as part of the HVAC system to enhance the quality of air inside the car for drivers and passengers.

Cabin air filters have been around since the 1970s, first used in the Rambler, but they quickly became popular with other brands such as Saab, then BMW, Mazda, and Ford Europe. Now, cabin air filters are standard in all vehicles because they have been proven to be such a success in not only keeping your HVAC running properly, but keeping you healthy and breathing well in the process.

Read more about ““What’s a Cabin Air Filter”

What does cabin air filter do?

The basic cabin filter, often referred to as “Particulate Filter” or “Pollen Filter”, is designed to trap pollen and dust.  Other filters include activated charcoal to adsorb harmful gases and undesired smells, often referred to as “activated charcoal filter.” Advanced cabin filters include an anti-bacterial layer that prevents the buildup of mold on the filter.

Obviously not all filters are equal. Some would offer higher filtration efficiency in terms of their ability to trap fine dust. Filters also differ in their life span before it clogs.

Ideally, a cabin air filter should block out all debris, dust, pollen, allergens, mold, and mildew, as well as pollutants such as carbon monoxide and sulphur dioxide. When looking for a new cabin air filter for your car, those features are the gold standard and should be carefully considered when you make your purchase. Imagine that your mouth and nose are at the front of your car, the level of your grill: everything that is blowing right into that spot, the exhaust, the dust, the particulates, the pollution--it’s all coming right into the cabin through the HVAC. Having a cabin air filter in your vehicle can prevent much of that from entering the cabin (and entering your lungs).

What is the best cabin filter for my car?

There are two criteria to consider when buying cabin air filter “Fit” and “Function”

Finding the right size and shape that Fits your car is the first step.  It is a simple Search by the year, make and model of your car. 

Next, is choosing the quality and performance you want. While there are many choices, it is important to know that not all filters are equal and there is a great variance in performance and quality.  Although some filters may appear similar, premium filters, like PureFlow, offer a higher efficiency in capturing fine dust, as well as coarse dust (10 microns or larger), while economy filters primarily filter out large particles. So, it is critical to verify the performance of the filter. Premium filters also include quality activate charcoal to adsorb harmful gases, as well as an anti-bacterial layer to prevent mold buildup on the filter.

What is Adsorption?

Often we confuse adsorption with absorption which are two fundamentally different processes. The difference between the two is critical in understanding the effectiveness of activated charcoal.

Absorption is occurring when molecules of one substance enters the bulk of another substance. During this process, the two materials come together and essentially form a new material.

Adsorption is when a substance attaches itself to another material. Adsorption happens at the surface level and does not create a new substance. It refers to holding molecules of a gas or liquid on the outside or internal surfaces within the material. ( dictionary.com ). When charcoal is activated, the surface area increases hundreds of folds and create gaps to adsorb gases. As such the activation quality determines the holding capacity and life span of the filter. 

What is the difference between engine air filter and cabin air filter?

Often consumers confuse engine air filter with cabin air filter. While the former is to protect the engine, cabin filter protects the driver and passenger. Engine air filter cleans the air before it enters the combustion chamber in the engine, where flow rate is critical to ensure optimal performance and fuel economy.  It is mostly designed to remove dust particles larger than 3 microns. 

Protecting the driver and passengers is a different task. Cabin filter are designed to eliminate find dust as small as 0.3 micron and others are also designed to remove harmful gases like carbon monoxide and sulfur-dioxide to name few.  More advance technologies for cabin air filtration like PUREFLOW., have the ability to weaken or inactivate viruses, germs and bacteria.  Such premium products have the capacity to eliminating odors and undesired smells. 

How often should I change my cabin air filter?

Just like your air filter at home, cabin filters for cars should be replaced once or twice a year. There are several factors that can impact the performance of the cabin air filters. Dust, road grime, leaves and other particulate matter that clogs the filter and slows the air flow. Humidity and moisture can be other factors that can impact the performance of the filter. 

In reality,  However, anytime you feel that the flow of air inside the car is being disrupted or weakened, it is time to replace the cabin filter. Some would prefer to replace the filter after pollen season and ahead of the hot summer and or after fall when dry leaves and debris are over. This is to ensure proper flow of cold air in the summer or hot air for defrosting in the winter.   Others prefer to replace the filter ahead of the allergy season. In essence, this is not a “mechanical” car question, it Is rather a judgment call that drivers and passengers need to make any time the flow of air inside the car is weekend weakened or a musty odor is sensed.  

What are the signs that it is time for a new cabin air filter?

One of the most common indications that it is time to replace the cabin filter, is a moldy or musty smell when the heat or air conditioning is on. The musty odor would smell like a wet towel left in the car for days. This is because pollutants, dust, mold and grime build- up on the filter and turns the filter to a source of pollution inside the car. A dirty cabin filter can make the air inside the car even more polluted than the air outside.  

The other most common sign that it is time for a new cabin filter, is a weak air flow out of the ventilation system. Often drivers confused reduced air flow in the AC with a mechanical problem in the car’s AC system, while it is likely a simple and inexpensive cabin filter replacement.  Clogged cabin filters add more pressure on the AC blower motor which can impact the blower.

Does cabin air filter affect the performance of AC in the car?

Yes! If your cabin air filter system is clogged it will impact the ability of the cooling and heating systems (HVAC) in your vehicle to do their jobs adequately.  A clogged filtration system will lead to poor air flow.  So, if you want your AC to work at optimum and healthy capacity it is imperative that you change your cabin air filter on a regular basis at least once or twice a year.

Where is the cabin air filter located in my car?

The most common placement of the cabin air filter is behind the glove compartment. Close to 70% of new cars, the cabin filter is located behind the glove box. Replacing filter is as simple as dropping the glove box, finding the access door to the filter, unlock it and remove the old filter.

In other models the filter is located under the cowl just in front of the windshield on the driver side. Other models may have it under the glove box or under the hood. PUREFLOW offers a complete location and installation guide for each filter when you search the car’s year, make and model.

How do I change my cabin air filter?

Replacing the cabin filter is an easy and quick job that should not take more than 10 minutes. PUREFLOW includes printed step-by-step instruction with each filter, this is in addition to instructional videos posted on the related product page. Most cabin air filters are located behind the glove compartment. Just simply open the glove box, drop it to expose the cabin filter access door, disengaging the door, pull out the old filter and inserting the new one, while paying attention to the air flow direction. On other cars it is under the cowl beneath the windshield, which in some case you may need some tools. Start by Searching your car’s make, model and year and you will find detailed instructions.

Can I replace a cabin air filter myself?

You can! It’s mostly a simple job in most vehicle. Most air filters are behind the glovebox, which usually means you have to remove it in order to get to the filter. It is easily accessible by releasing the glove box from its fasteners; dropping it down to expose the access filter’s door. All PUREFLOW filters are shipped with a printed step-by-step instruction. This is in addition to instructional videos posted on the related product page. . PUREFLOW  offers a complete location and installation guide for each filter when you search the car’s year, make and model.

What if I didn’t change the cabin air filter for a long time? 

A dirty cabin air filter can become a source of pollution inside the car, as dust and mold builds up on the filter and disburse filthy air inside the car for drivers and passengers. Simply, the air quality inside the cabin will really suffer.

It would also impact and slow down the flow of air through the ventilation system. The more clogged the air filter becomes the harder the heating and cooling system has to work, which adds pressure on the blower motor and thus shorten its life. 

What is the purpose of the directional “Air Flow” arrows on the filter?

The filtration media of the cabin filter, especially premium ones like PUREFLOW, are carefully engineered to allow maximum air flow and maximum dirt holding capacity. In order to achieve that, the media is designed like an air funnel, where the air flows form the dirty side, with larger pores, to the clean side which has finer pores. Installing the filter in a reverse orientation, can restrict the air flow and cause the filter to clog sooner. 

How do I identify the air flow direction in my car?

It is very important to validation the air flow direction in your car’s ventilation system. This can be a simple task once the old cabin filter is removed. Simply turn the ignition on and turn the air vent on to the max. Then get a flat sheet of paper and insert it into the filter housing. The air flow will push the paper to the clean side. 

Mechanics often take a note of the direction of the air flow arrow on the old filter before removing it, which can be a safe choice in most cases. However, you may run the risk that the previous installation was incorrect.

How do I identify the air flow direction on the cabin filter?

Most cabin filters would have a direction air flow on the side panel. All PUREFLOW cabin filters are marked with 2 arrows pointing to the direction of the air flow. However, in case the arrows are missing, all PUREFLOW filter are designed with a gray side, which is the dirty side and a blue side, which is the clean side. The air flows from the dirty to the clean side, meaning from the gray side to the blue side.

This website uses cookies to ensure you get the best experience. Learn more
Ok, Got It

Shopping cart