Motorhome Windscreen Condensation 15 Comments


How to get rid of that annoying condensation.

When it’s cold and wet outside, the windscreen in the morning gets absolutely wet through on the inside. Warm air in the van condenses on the cold glass and creates lots of condensation. You heating creates it and so does your exhaled breath. There are a few options to help reduce this problem all with varying results and costs:-


  1. Opening a window.

    • Pros
      • Costs nothing.
      • No storage requirements.
      • Quite effective at reducing the condensation.
    • Cons
      • Lets the warm air out and cold air in.
      • Remember to close the window before driving off.
      • Does not eliminate the problem.
  2. Just use a cloth.

    • Pros
      • Cheap and easy.
      • Storage not an issue
    • Cons
      • Not very effective and leaves lots of residual water.
  3. Buy a windscreen cover for the outside of your vehicle.

    • Pros
      • They have the advantage of keeping the inside of the vehicle warmer by keeping cold air off the glass.
      • Very effective against condensation with little or no residual water.
    • Cons
      • They are can be expensive to buy (they can be over £350).
      • High storage space requirements.
      • Can be a hassle to install.
      • Might not eliminate the problem.
  4. Window Vacuum.

    • Pros
      • No too expensive. (under £70)
      • Small storage requirements.
      • Removes all the water from the glass.
      • Can also be used at home.
    • Cons
      • Not the cheapest option on the market.
      • Needs recharging every so often.
      • Better than using a cloth.

We considered the pros and cons of each and opted for the window vacuum, there are a few on the market but we opted for a reputable brand and bought a Karcher WV2 window vac. It works brilliantly for getting the water and condensation off, whether its the windscreen or a conservatory back home. The battery life provides many days of use and charges up in 1-2 hours depending on how flat the battery gets. Sadly the unit requires 240v electricity but we have an inverter so it’s not a problem. However……

I had a look at the electrical output of the charger and guess what? 5v at 600mA. If it had a different connector on it could be charged up via a USB socket, so now I need a spare charger for it so I can cut the charger off and fit a USB plug instead, i can then plug it into a cig lighter adapter or computer to charge it up then instead of having to use the 240v inverter. If you have any thoughts please feel free to share.

Well it looks like Alistair (in the comments section) tried the DIY USB wire idea and it works perfectly and kindly offered to make us one too.


Verdict: Well the Karcher WV2 window vac is a good compromise that works perfectly for us and would definitely recommend it.


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15 thoughts on “Motorhome Windscreen Condensation

  • Ian Parsonage

    Does anyone know if Alistair is still around please as I would like a link to the plug he used to make the Karcher charging lead on either Amazon or Ebay or failing that a brand name would suffice! Many thanks!

    • Bumble Crew Post author

      Sorry for the delay in replying, You can use any USB cable but just a cheap charging cable is best as they only have 2 wires, just cut the plug off leaving a little wire left attached and solder the positives together and also the negatives, use a voltmeter if unsure. Still never got around to doing myself yet.

  • David Brier.

    We also like the Karcher for the screens when we don’t use the external silver screens. We also use it to dry out the shower, you’ll be amazed how much water it takes in and the colour of it! We now wipe down the shower walls after use and dry with Karcher. Great thought by Alistair re the USB plug, thats my next job.

    • Bumble Crew Post author

      Hi David, we just use a small squeegee for the shower but the Karcher does make like work of the screen. Good look with the USB connection it would be an easy mod, after saying that I still haven’t got around to doing it.

  • Aaron Hill

    Hi guys, we simply use a small 40p window / shower cleaning squeegee blade from IKEA and a (just used) cereal bowl to scoop up excess water on our windscreen. We’re quite efficient at it now, but any spilled drops can be wiped up with a cloth, giving the dash a once-over tidy dusting too. Works a treat. A

  • Alistair

    The wire is very easy to make, £4.99 replacement plug eBay/amazon & £0.78 for a diy USB plug two drops of solder, job done & it works !

    I bought 10 USB plugs, seamed a shame to just post one, so if you want one let me have your address .. the least I can do for all the wonderful information !

    • Ian Parsonage

      Does anyone know if Alistair is still around as I would like a link for the Karcher plug on Amazon / Ebay if possible or a brand name for the plug so that I can make a lead up for usb charging?

  • Gary Davies

    I saw a tip that suggested putting cat litter (which is designed to absorb moisture) inside an old sock. Not tried it myself.

    • Bumble Crew Post author

      Hi Gary, I think the problem with it though is how much can it actually absorb, it’s the same as the shop bought small dehumidifiers they sell I suppose but I don’t think it would be that effective to be honest, leaving a window or skylight open a little helps a lot as it lets the moist air out, but sadly the warm air goes with it. If you have some kitty litter then give it a go and let us know how well it actually works, we’d love to know if such a simple system could be effective and I’m sure other people would too.

  • Paul Hillman

    I have just come across your blog and I am really enjoying the read I would like to ask if you found a usb charger for your Karcher we are hoping to do similar to what you are doing next year and I am getting loads of ideas from you experience.

    • Bumble Crew Post author

      Hi Paul, i never got around to it, it should just be a case of putting a USB plug on the end of the lead instead of the charger, it was all a bit rush, rush as we left, it soon charges on the inverter though, we just charge it whilst driving usually. If you get round to trying it let us know.