condensation inside the car

How do you fix condensation inside a car?

Condensation inside the car is something that affects all vehicles. We’ve put together a quick primer on what causes car condensation and how to reduce its effects.

What is condensation?

Condensation forms when warm air containing moisture comes into contact with a cold surface, such as your car window. When the warm air meets the cold air, the moisture in that warm air condenses onto that cold surface.

Read more: Should you fit winter tyres in cold weather?

On a car windscreen, this moisture takes the form of hundreds of tiny water droplets that, from a driver’s perspective, looks like a fog.

condensation inside the car

What causes condensation inside a vehicle?

One or a number of the following things could cause condensation inside the car:

  • Wet clothes/shoes/pets – water on these items will slowly evaporate into the cabin air or, if heavily soaked, cause the seats and carpet to become wet.
  • Breath – when you or your pets breathe, that exhaled air contains a large amount of water vapour which is released into the cabin.
  • A water leak.
  • No circulation of fresh air.

condensation inside the car

Are new cars more prone to condensation build up?

Modern cars have much better seals, meaning they tend to be more water tight. This means that it’s more difficult for any air inside the vehicle to get out.

If movement is created with a fresh air source, moisture levels will decrease. Well-sealed and insulated newer cars means this movement cannot happen.

Read more: Driving in winter? Our top tips show you how.

Increased insulation also allows modern cars to stay warmer longer after being parked; the longer the air inside the vehicle is warmer than the air outside, the more condensation will appear on the cold windows of the vehicle.

condensation inside the car

How can I reduce condensation in my car?

As condensation collects in the air inside the cabin, the level of moisture will increase. If this air is not vented to the outside then the condensation problem will increase.

The most efficient way to remove moisture from the air is to use the vehicle’s air conditioning system. This system draws air from the cabin through an evaporator, which causes moisture in the air to condensate in a controlled way and drain out of the vehicle.

If the cabin air is not regularly refreshed then condensation will accumulate, as the moisture-filled air will not be removed. However, you can force this by changing the re-circulation feature from internal to fresh air.

Don’t forget the demister function, either. That’s designed to clear the windscreen of condensation. This works by directing fresh air onto the windscreen, which has the effect of drying the inside of the glass.

condensation inside the car

If the features of the heater and air conditioning system are used as above, then the amount of condensation inside the vehicle will be reduced. However, it will never be removed – moisture will always be present inside the vehicle.

Believe it or not, one of the key ways to keep condensation at bay is by simply keeping the insides of windows, particularly the windscreen, as clean as possible. A thorough clean of the windscreen will lessen the likelihood of condensation forming, and ensures that any that does form is removed quicker by the demisters.

You can also buy a car dehumidifier bag. This is a small bean bag full of silicone balls that sits on the top of your dashboard and soaks up moisture from the air inside your car at all times.

 

Comments (11)

  1. It’s no from the headlamps the drip is coming from under the car. It is a clear water that is dripping. Is that normal? The service representative told me that is normal even I did not use A/C.

    1. Hi Arnold,
      Thanks for getting in touch. If a drip or puddle is present from under the vehicle, this is normal when the A/C is in use. The moisture taken out of the air will be drained from the system, hence a puddle may be present underneath the vehicle, particularly on hot days. It may however be worth getting the vehicle checked by your service centre, just to be sure there isn’t any other issue.
      If there is condensation inside the vehicle, we’d suggest using the A/C – this will help remove moisture from inside the cabin. If you have the air recirculation function turned on, it may be worth switching this function off, as air entering the cabin from the outside will generally contain less water vapour.
      Hope this helps.

  2. I have a 2016 Camry and it is regularly being service at Toyota Service Center. I notice there is a drop let’s of clear water in my car every day and it’s more than normal. I went to the service center yesterday the customer relation person told me it’s normal. It’s called condensation. How can I eliminate to much condensation on my car. Is it normal? I get paranoid.

    1. Hi Arnold,
      Thanks for getting in touch with us. We believe you are talking about condensation inside the headlamps. If this is the case it is extremely normal (and more so during winter when the car is exposed to very noticeable temperature changes). Regardless of the size of the condensation if it doesn’t go away in 10 or so minutes then we’d advise going to your local Toyota center.
      Hope this answered your question.

      1. James

        Hi, my niece has a Toyota Aygo which was recalled due to a problem with seals some time ago. What the problem was I am unsure. The problem she is having now is that the inside of the care is constantly wet, and I don’t just mean damp. The carpet in the boot is actually soggy, all the windows wet with water, on a cold day she also has to scrape all the windows inside the car. Recently she got in the car and turned on her CD player, it continuously cut out and made funny noises. When she ejected the disc it had water on it. She dried it off and tried it again and it worked fine but it’s happening more often. Her interior light stopped working so her partner removed it to change the bulb only to find all the insides rusty. Is this a common fault with the Aygo???

        1. Hi James,
          Sorry for the delay. After speaking to our Technical team, it seems that, from your description, there is a water leak in the vehicle. We’d advise having the fault investigated by your local Toyota Centre in order to identify the root cause. You will be able to find your closest dealer here: https://www.toyota.co.uk/find-your-dealer.json. Thanks.

  3. I have a 65 plate Aygo & regularly suffer condensation after the car has been left on the car park at work for 12 hours. I return to the car & the inside front screen is soaking wet & when its below freezing I have to scrape the inside as well as the outside.

    I also find that the demist is very poor on the drivers side of the windscreen leaving about a quarter of the screen misted over when the rest has cleared (with air con switched on), never use the re circulation setting so its not that.

  4. I sincerely hope this article wasn’t hastily published in response to the number of owners complaining about TSS unreliability!

    1. Hi Ian,
      No, we didn’t make this in response to Toyota Safety Sense. This is just a general winter driving tips article. Many thanks.

  5. Easily the most important tip above, is to switch off recirculation mode. So long as there is sufficient through flow, condensation will mostly be kept at bay, even without the use of aircon.

    btw ‘condensate’ is the liquid that builds up after moisture has condensed, it isn’t a verb!

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