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How To: Cleaning Your Vents

car air vent

Your car’s ventilation system serves an important purpose: filtering and circulating air to keep you as comfortable as possible inside your car.  Air is constantly flowing through your car, and is being conditioned to be colder or warmer to cater to your preferred air temperature. This task is ongoing for your car, and in summer and winter when we often turn to heating and cooling, our air vents can get abused. After prolonged use without any cleaning, air vents can build up with dust and odour particles (especially if you live in a humid environment as moisture holds odour more so than dry air) which can settle in these vents and develop a musty smell in your car. Over time, this smell can intensify, making your car’s scent more unpleasant. So, if you start noticing a stuffiness, it’s a good sign to get your vents clean before things escalate – and we’re here to show you how. Firstly, let’s have a brief look at what we’re working with in a ventilation system.

How an Air Ventilation System Works

The air ventilation system in your car is a much simpler system that you’d think. Air is sucked in through a large duct at the front of the car when the car is in motion; this is due to the high pressure created which forces air in when you’re driving. There are also smaller ducts along the grill at the top of the bonnet, under your windscreen. As this air enters your car, it is either heated or cooled, or if you’re just using a fan setting, it is simply passed through your open air vents and distributed around your car. Air vents located at the rear of your car also work to suck this air out, allowing a constant flow of air through your car. That’s it! 

Some cars allow a closed loop of air to circulate your car – this means that the air inside your car is recirculated so that air isn’t expelled after entering your car. Your vents will suck out your car’s air and reheat or re-cool it and push it back into your car. This is a great setting for when the air outside is smelly, humid, or hot as your car won’t have to work as hard to keep air cool and fresh. 


To heat the air in your car, the ventilation system pushes it through a water-heated matrix/radiator. Fans further assist in pushing the air through the car. Essentially, there are two main types of heating systems. The first is water-controlled – the temperature of the air is regulated by hot water running through the matrix which varies to create the right temperature. The other is through an air-blending system whereby the matrix is at a constant temperature and air is temperature controlled through the blending of cool and warm air released by flaps that open and close.

woman in car driving air vents shutterstock


Cooling is a slightly different story. All car air conditioning systems run on a high-pressure gas called ‘refrigerant’. This gas is compressed (in the compressor, no less) and turned into a fluid that passes through the condenser which removes any heat from the refrigerant. The refrigerant is then turned back into gas as it passed through the expansion valve; after this, it goes into the accumulator that removes moisture from the gas and transfer it to the evaporator – as air in your vents passes the evaporator, the refrigerant draws in any heat from the air so that only cool air makes it beyond the evaporator. Viola – that’s your cold air. 

As there is a lot of moisture passing out of the air in the vents or around it, there’s potential for this moisture to dwell in your vents and cause odour and bacteria to grow. This is exacerbated by those that live in humid weather and go extended periods without using their air conditioning or even fans. Overall, it’s good for yourself and your car to clean your vents once in a while. 

Benefits of Cleaning Your Car Air Vents

Not only will you notice an improvement to the quality of air in your car, but you will benefit from cleaning your vents in the following ways:

  • Removes any allergens and dust which cause irritation 
  • Helps keep your car smell pleasant
  • Prevents bacteria from developing (especially if there is moisture present)
  • Prevents mould growth 
  • Improved conditions for individuals that suffer from asthma and other respiratory issues
  • Maintains the quality and longevity of the air vents
  • Prevents particles and dirt building up which slowly deteriorate materials

How to Clean The Air Vents

Finally, down to the nitty-gritty – cleaning your air vents. They should be cleaned from the inside and the outside. An easy way to clean them from the inside is to get a fine brush and dust inside each individual air vent. Whilst brushing and loosening the dust, hold the vacuum head close by to suck all the dust away from the air vent. Make sure the brush is soft and fine so not to scratch or damage the delicate slats. Brushes made from micro fibre are the best option. Make sure the vacuum you are using is strong. Pair the use of a brush with disinfectant or cleaning spray to tackle dirt and grime at the opening of your vents. 

If you have access to a steam cleaner, this can also be an effective way to get deeper into the vent and give it a good clean. This also works as a disinfectant. Just ensure you dry the vents after you steam by blasting some air through them. 

Onto the inside – from the outside of your car, spray compressed air into the exterior air intake vents. Make sure the ventilation system is running while you do so to allow air to escape. A musty smell can also be the cause of a cabin air filter that’s become too dirty and blocked up; you can easily change this yourself to get the ultimate freshness in your car

If you’ve followed all of these tips and the smell is still lingering, this could be a sign of mould growth in your air conditioning or heating system – these are slightly more complex to reach and clean. In this case, it’s best to get in touch with a professional. 

Repair Plans Up in The Air?

Constant heating and cooling can stress the glass within your car, causing chips or cracks. It’s best to get these sorted sooner rather than later. Repairs are quick, easy, and much cheaper than replacements – and at Novus Autoglass, we make it easier by coming to you. We also ensure the repair job will last with our lifetime guarantee, meaning that the repair will last for the remainder of your car’s life. So, if your windscreen or windows are looking worn out, book in a repair with us soon.

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