What does a cabin or pollen filter do? Common problems and replacement costs

With summer fast approaching, drivers should be getting their air conditioning in full working order. Part of this is having a clean cabin filter.

Modern vehicles have many pieces of technology and comforts that make the driving experience more enjoyable – but having cooler air in the vehicle on a hot day is important for many reasons.

This car maintenance guide looks at everything you need to know about cabin and pollen filters.

What is a cabin filter?

Air conditioning keeps your vehicle in a comfortable temperature during the warmer months for you and your passengers.

A cabin filter is a component within the air conditioning system that cleans the air as it passes through the vehicle's HVAC system. This is the part of the vehicle that also controls the heating and ventilation.

Its main function is to filter out dust, mould spores and other airborne contaminants that can end up creating problems for everyone in the car or damaging parts of the vehicle.

They can be found behind the dashboard, under the glove box or under the bonnet by the windscreen. This can depend on the make and model of the vehicle, as well as how old it is.

Cabin filters provide an important function of improving air quality and extending the life of the HVAC system.

What is a pollen filter?

A pollen filter is a type of cabin filter that also traps pollen and other allergens within a vehicle.

In months where there is a high pollen count, it can help drivers with hay fever.

It uses an activated carbon layer that can absorb these allergens, as well as odours in the vehicle.

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Signs of a faulty cabin filter

Cabin filters will not last the lifetime of the vehicle and will need to be replaced – so here are the signs to look out for.

• Reduced or inconsistent airflow
• No temperature change when adjusting the settings
• Strong smells coming from inside the HVAC system
• Foggy windscreen

Checking the state of your cabin air filter is something that should be a part of your regular car maintenance. It can also be a part of your annual service – so check when booking your next one.

How long do cabin filters last?

When it comes to the lifespan of a cabin filter within a vehicle’s HVAC system, they usually last up to 15,000 miles – or at least once every 18 months.

However, this can vary depending on a variety of factors including how often it is used, the average temperature and humidity, quality of the filter, quality of the HVAC system, levels of pollutants and pollen, levels of dust and dirt and how often the air conditioning is used.

READ MORE: UK heatwaves - data and advice

How to change your cabin filter

As the cabin air filter can be found in several places, the first step is to search the make, model and year of your vehicle and see where it is located.

It will likely be under the glove box or dashboard – or under the bonnet in its own housing near the windscreen.

Here are the next steps you should take to replace your cabin filter:

• Make sure the engine is turned off: Ensure there is no electricity or power running through the engine. Next, you’ll need to locate where the filter is.
• Remove the filter cover: This will involve using a screwdriver or unclipping it from the housing.
• Remove the old filter: It will either slide out or you’ll need to remove it from the unit.
• Clean the housing: This will help increase the lifespan of the next filter and remove any pollutants that could lead to other issues.
• Install new cabin filter: Make sure it is orientated properly and is the correct size for the housing.
• Reattach the filter cover: Screw or clip it back into place and clean up any dirt or debris.
• Turn on the vehicle and take the car for a quick drive: Test the HVAC system, including heating and cooling, as well each of the fans.

What does a cabin filter look like?

A cabin or pollen filter is a block sized object that is filled with rows of paper, cotton or synthetic mesh to trap dirt, dust and pollen. The filters are white or bright in colour.

When a cabin or pollen filter gets dirty it turns black or dark in colour. It may also have debris trapped between the filters.

How much does it cost to replace a cabin or pollen filter?

Drivers can expect to pay up to £60 for parts and labour to replace a cabin or pollen filter.

This price can vary depending on the make, model, and type of vehicle - as well as where in the country the work is being done.

If you need to have your cabin and/or pollen filters replaced, you will need to visit and RAC Approved Garage or somewhere that an experienced mechanic can carry out the work.

How often should you change your cabin or pollen filters?

It is advisable to change the cabin or pollen filter every 12 to 18 months – or every 10-15,000 miles (whichever comes first).

Every vehicle manufacturer will state within the vehicle owner’s manual when they advise you should change your cabin or pollen filters, so this advice may differ depending on your make of car.

When does pollen season begin and end?

Here are the dates for pollen season in the UK:

^{Source: University of Worcester National Pollen and Aerobiology Research Unit Regional Pollen Calendars.}

Cabin filter vs air filter: what's the difference?

Although they sound similar, a cabin filter and an engine air filter perform very different jobs. A cabin filter, sometimes known as a pollen filter, cleans the air entering the vehicle's cabin through the heating, ventilation and air conditioning (HVAC) system. Its purpose is to remove dust, pollen, mould spores and other airborne particles to improve air quality for the driver and passengers.

An engine air filter, on the other hand, protects the engine by preventing dirt, dust and debris from entering the combustion system. A clean engine air filter helps maintain performance, fuel efficiency and engine longevity.

Signs a cabin filter needs replacing

• A blocked or dirty cabin filter can lead to:
• Reduced airflow from the vents
• Weak air conditioning performance
• Unpleasant smells inside the vehicle
• Windows taking longer to demist
• Increased allergy or hay fever symptoms while driving

Signs an engine air filter needs replacing

• A worn or clogged engine air filter may cause:
• Reduced engine performance
• Poor fuel economy
• Engine hesitation during acceleration
• Unusual engine noises
• Excessive exhaust smoke on some vehicles

How often should they be replaced?

Most cabin or pollen filters should be replaced every 10,000 to 15,000 miles or every 12 to 18 months, depending on driving conditions and manufacturer recommendations.

Engine air filters generally last longer, with many manufacturers recommending replacement every 15,000 to 30,000 miles, although this can vary significantly depending on the vehicle and driving environment.

Replacement costs

Cabin and pollen filter replacement is relatively inexpensive, with drivers typically paying up to £60 including parts and labour.

Engine air filter replacement costs are often similar, although prices vary depending on the vehicle make and model. Premium vehicles and filters can cost more, while many engine air filters are simple enough for experienced DIY enthusiasts to replace themselves.

In short, the cabin filter protects the people inside the car, while the engine air filter protects the engine itself. Both are inexpensive maintenance items that can help keep your vehicle running efficiently and comfortably.