Car Air Filter: 5 Things You Need to Know

Driver and passenger wearing face masks to protect them from harmful bacteria in cabin air system due to lack of air filter change

The air filter in your car keeps your cabin smelling fresh and dust and pollen free. If your car’s heating and ventilation unit is struggling to pump out a good flow of air, the air smells stale or musty or your allergies or hay fever is playing up more when you’re behind the wheel, your cabin air filter is likely to blame.

This is the filter that forms part of the car’s heating, ventilation and air-conditioning system – HVAC for short. The cabin air filter is the one part of the car most drivers take for granted. But from time to time, it requires routine maintenance. So, what do you need to know about the air filter in your car?

By the end of this guide you will understand:

  • How an air filter works
  • When cars started using them
  • How often to change a cabin air filter
  • How you can change it yourself
  • The cost of a cabin air filter

 

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When Did Cars Start Using Cabin Filters?

Filters for the ventilation system became commonplace in 2000. Before then, it was usually luxury cars or those with an optional air-conditioning system that featured a filter. If you have an old car, you’ll know it lacks a filter because the ventilation system will occasionally blow in bits of leaves and dust.

 

How Does a Car Air Filter Work?

All the air channelled through a car’s ventilation or air-conditioning system is passed through a filter before it reaches the cabin. Denso, a manufacturer of filters for car makers, says the most common type of cabin or pollen filter is typically made from five layers of fleece-like material. This means it can trap particles as small as 0.001 microns. That’s tiny; a human hair is typically up to 100 microns thick.

Like vacuum cleaners, many of the latest cars feature filters with carbon (charcoal) filters. These are claimed to be ultra effective at capturing minute particles and can prevent the build-up of bacteria and fungus.

 

When Does A Cabin Air Filter Need Changing?

 

Different car cabin air filters arranged in front of a yellow background
Your cabin air filter can come in a variety of shapes and sizes.

 

Different car makers may call it different things: cabin filter, microfilter or pollen filter. They also recommend different intervals for how often a cabin filter should be changed. But the one thing they agree on is it’s a job that needs to be done.

The UK’s most popular car maker, Ford, says that the cabin filter of a 2016 Focus family hatchback needs changing every 15,000 to 20,000 miles. However, it adds that this could be done more frequently if the driver (or any passengers) suffer from allergies, or if the car is used in dusty environments, such as building sites or dirt roads.

By contrast, BMW recommends that owners have the pollen filter changed every time their car requires an engine oil change. The timing of this varies according to how the vehicle is being used, as modern BMWs feature variable servicing intervals.

Regardless, you should change your air filter on a regular basis. With BookMyGarage, our full and major car services replace your air filter as standard, with a major service also replacing your pollen filter. To keep your cabin fresh and bacteria free all year, book a full or major service online now. Just enter your reg number and postcode to compare and save on thousands of fast fit, franchise and independent garages near you now!

 

 

Can I Change The Air Filter in My Car?

In theory, yes you can change your car’s air filter. However, some manufacturers make it easier than others. Check your vehicle handbook first. This should show its location and, if looks easily accessible, you can order the part online, using the vehicle registration or chassis number to verify that it’s compatible.

Your car air filter may be hidden behind the glove box. Depress a couple of catches and the glove box drops out of the way, revealing the filter. It should slide out on a tray and can be removed and replaced using just your hands. However, it could also be hidden away in the engine bay. Tools are then required to get at them. In this case, any local garage will be able to remove and replace the part for you.

 

How Much Does A Cabin Air Filter Cost?

Taking the Ford Focus 1.0 petrol as an example of a popular family car, the price of filters available ranges from £5 to £25. Someone buying a pollen filter for a BMW 320d could expect to pay between £20 and £55, depending on whether or not they wanted a standard fleece filter or carbon-based part.

 

Recap

A car air filter is vital for your health and preventing allergen flare-ups as you drive along. It keeps the air clean and fresh and filters harmful dust and pollen out of the cabin. You should replace yours regularly but, as there is no standard interval, you should check your vehicle handbook for your manufacturer recommendation. Fortunately, an air filter isn’t that expensive if you choose to replace it yourself.

 

 

James Mills

James is a motoring journalist and former magazine editor at BBC Top Gear and Auto Express. He has scooped, reported on and reviewed most new cars of the past 20 years, and currently contributes to the Driving section of The Sunday Times.