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How To Stop And Prevent Condensation And Moisture In Motorhomes & Campervans?

Enjoying camping life in cold climates can be fun, but not when you have to deal with an enemy – condensation.

You may think that’s an exaggerated statement, but best believe that it isn’t, and the best solution to condensation is preventing it from happening.

Most campers use their RV full time, and while it may seem like no biggie having to deal with condensation, it is. Condensation goes beyond a thin film of moisture forming on the windows; excess moisture can ruin upholstery and cause wood furniture to rot or metal to rust, not to mention the associated health issues.

In this article, we’ll discuss the tricky problems caused by condensation, how to prevent it, and of course, how to solve damp air problems. The truth is that campervan condensation is no joke if the well-being of your RV is a priority for you.

What is Condensation?

What is Condensation?

Condensation is just the mixture of warm air and temperature difference. In other words, it occurs when the water vapour in the air comes in contact with cold surfaces, like your windows or the sheet metal of an RV or campervan body.

Imagine putting hot tea inside a glass of water during winter; the temperature difference will cause a film of water droplets. The same happens with your campervan; hot showers and cooking can quickly cause moisture buildup, forming condensation.

Absolute Humidity (AH)

Absolute humidity is the total amount of water vapour (moisture) the air contains. More water vapour means that air is more humid.

Relative Humidity (RH)

The relative humidity is the amount of water vapour in the air at a specific temperature in relation to the maximum amount of moisture the air can hold at that same temperature. When the air passes the saturation point, it can’t hold more water vapour.

RH is affected by the surrounding atmospheric conditions of a particular place. And when the relative humidity of a place is high, it means the air-water mixture is highly humid as well.

To avoid condensation, you need to lower the relative humidity, and to do that, you need to increase the temperature.

Dew Point

Dew point is the term used to explain the temperature to which air needs to be cooled to become saturated with water vapour. At the dew point (relative humidity=100%), water vapour begins to condense.

Below the dew point temperature, moisture buildup occurs and is released in the form of condensation.

What are the signs of condensation in a motorhome?

You may think your motorhome isn’t at risk of condensation issues, but you’re wrong!

The main way to prevent condensation is having constant air exchange through proper ventilation, but how do you know what traces to look out for when it comes to motorhome condensation?

Mould Patches

Mould Patches

When there’s inadequate air circulation in your motorhome, it’s easy to start seeing mildew and mould inside your RV; this is especially true when it’s cold outside.

Check by the side of your mattresses, behind the corners of your cushions, and anywhere you feel air usually gets trapped. If you spot mould stains there, then there’s a high chance that condensation is happening.

Most campervan owners use a damp cloth to clean the patches away, but that’s not the best way to completely get rid of them. Eliminating the main culprit is a must, or you’ll exhaust yourself daily.

Spongy Surfaces

It should be a great concern when touching the walls creates a dent, as it indicates that a certain amount of damp air has already infiltrated your camper, causing the interior to become soft to the touch.

When this happens, you’ll probably need a professional investigation to help figure out where the problem is from and how to improve airflow.

Musty Odour

One beneficial thing about the RV lifestyle is the fresh air that comes with it, but what happens when you start your morning with a strange and musty smell?

Ideally, you might not immediately notice what the matter is, but after a few months, or even hours, it might worsen.

If that’s the case, there’s a high chance that dampness in your RV is causing the smell. It may start as a small leak, but if left unchecked can cause severe structural damage.

Black Spots

When you see black spots around the windows of your motorhome or even on the roof lights, it indicates that you need to have your RV checked. Sometimes, there might be pinkish stains on the walls of your RV, so look out for those too.

Don’t wait until it gets out of control before contacting professionals. You might end up spending more money if you delay!

Nicking condensation at its beginning stage will help you control it better.

What are the dangers of condensation in your motorhome?

There are several problems condensation can cause, which is why regulating temperature is essential.

Some of the dangers damp problems cause include;

  • The formation of mould can result in health complications
  • It can cause metal window covers and cabinets to even rust
  • When your campervan is saturated with moisture-laden air, it can cause a foul stench
  • Full-blown condensation can cause cracks in the walls

What causes condensation in a motorhome?

Condensation forms because of an increase in humidity. The bigger question should be, what causes increased humidity in your campervan?

Body Heat and Breathing

Simply sweating or even the natural heat emitted by your skin and breath over time is enough to raise the temperature inside your RV. These two actions can increase the moisture in the air and form condensation, especially if you don’t have good ventilation in your camper.

Having pets doesn’t help in controlling moisture. Instead, it creates more humidity in your motorhome.

Drying Wet Clothes

Drying Wet Clothes

Keeping damp clothes inside your van to dry will increase the level of moist air because the damp air gets trapped inside the camper van.

If you don’t have externally ventilated air heaters that can generate dry heat inside your motorhome, it’s best to dry your clothes outside.

Wet Pets

Taking your pet travelling can make it more fun, or sometimes it’s just a necessity because you can’t leave them at home and go on your trips.

But allowing wet dogs to stay in the living area can increase the moisture level in your motorhome and create condensation.


When you shower and keep your bathroom door sealed, it traps moisture inside the bathroom. So, after showering, you open the door, and the water vapour escapes and saturates the cold air outside.

Heat Source

One easy way of preventing condensation is limiting your use of a liquid propane heater. Burning propane introduces more water vapour into the air, thereby increasing temperature, compared to a diesel-fired heater which produces significantly less water vapour.

Using a wood stove is an excellent way to stop condensation, especially during cold weather, plus wood stoves act as moisture absorbers. That’s because they help to suck in the humid air in your camper and reduce condensation on any cold surface.

However, if you must use a propane heater, use a vent fan or keep your windows open for constant airflow.

Cooking Method

The fastest way to create moist heat in your vehicle is by boiling water on a cold day. The cold exterior surface of your motorhome will contrast with the heat inside and cause moisture to build up.

Often, camper owners don’t like opening their windows while cooking, especially during winter, because they don’t lose the warm air inside the campervan. However, this is a quick recipe for condensation because the heat inside the camper will rise above the outside temperature, causing condensation to form.

You can reduce dampness inside your RV by having proper airflow and keeping the door open when cooking inside your vehicle. You could also try installing an extractor fan in exhaust mode to suck out moist air.

How To Control And Stop Moisture And Condensation In Your Motorhome?

We’ve already established that condensation can wreak great havoc on your motorhome, and a good solution is always “prevention”. Let’s look at some remedial action possibly required to prevent condensation inside your motorhome.

  • An open window or open roof will help water vapour from getting stuck in your motorhome
  • Always make use of campsite facilities when you can to avoid constantly using your motorhome shower
  • Don’t place wet towels inside your camper as it increases moist air in your living space
  • Invest in vent fans as it prevents condensation
  • Proper insulation of your motorhome should be a priority as it acts as a vapour barrier
  • Use small portable dehumidifiers
  • Don’t keep damp materials inside your cupboards
  • Use extractor fans when cooking to make the insides of your motorhome cooler; if you can, don’t cook inside your van
  • Most condensation happens during showers, so put a few vapour barriers in your bathroom
  • Remember to check your cushions as they absorb water too.
  • Covering exposed metal will reduce the condensation forming on the surface area
  • Always use good quality window shades to create a barrier between the outside of your motorhome and the insides.
  • If you must shower in your bathroom, ensure you wipe the shower to reduce the amount of water vapour in your motorhome.
  • Properly insulate your floors and ceilings during both winter and summer
  • Remember to keep things clean and fully dry so condensation doesn’t occur
  • Ensure there’s adequate airflow in your motorhome. If there isn’t install a Maxxair fan or similar on the ceiling, so air can circulate better
  • Spread your wet towel under your awning
  • Use a vapour barrier on the warmer side of your motorhome
  • Cooking with a pressure cooker is a sure way to reduce moisture in motorhomes
  • Don’t spread your wet towel inside the camper after washing
  • Get a cover for your windscreen to stop condensation in the driver’s compartment
  • It’ll help to use candles when you want minimal illumination
  • Be sure there are no leaks; check the ceilings and walls for any holes, and if you find one, make sure you repair it as soon as possible if you intend to reduce condensation and also stay warm
  • When storing your motorhome, use a breathable cover to prevent water ingress
  • Don’t use liquid propane heaters, as they generate more moisture
  • Use a mattress underlay to promote proper airflow
  • Use a reliable clothes dryer vent
  • To stop condensation and moisture in motorhomes, make sure you fix all worn seals
  • In instances where you’ll leave your motorhome for an extended period, open up the cupboard doors, and spread out your mattresses, so there’s enough ventilation
  • Install an externally ventilated air heater to help balance the humidity level outside and inside
  • Use moisture-resistant materials for upholstery and other furnishings to help prevent damage

Avoid Condensation in the Bathroom

Your bathroom is another space for storing moisture. You’ll always need to be careful when opening the doors to avoid creating a high influx of steam into your living space, which will no doubt form condensation.

One way to prevent condensation from happening inside your bathroom is to use moisture absorbers or an extractor fan. You could even place a tray of cat litter or salt to soak up moisture. And make sure every opening is properly sealed. That way, no moisture gets out. Instead, the absorber sucks it in to ensure your space is dry.

Can you use an electric dehumidifier in a motorhome?

Can you use an electric dehumidifier in a motorhome

Electric dehumidifiers absorb moisture from a cold surface before condensation forms.

They work the way an air-conditioner does, except that instead of blowing cool air, dehumidifiers cool wet surfaces so that condensation doesn’t form.

To keep your van warm while still keeping the moisture level in check, you need to use an electric dehumidifier. Don’t worry about safety – carefully follow the manufacturer’s instructions and tips when using the dehumidifier, and you’ll have no issues.

Also, remember it’s not wise to use it for long periods without emptying it, so never forget.


  • Easy to use, especially during road trips
  • Prevents musty odour and reduces rusting
  • Lowers the risk of mould growth
  • Plugs in close to the bed without worrying about it affecting your sleep at night
  • Safe and efficient at keeping moisture at bay
  • Alleviates allergies and reduces dust mites


  • Requires electricity as you cannot just hang it anywhere
  • Takes up space
  • Needs regular maintenance
  • Noisy sometimes
  • Increases the energy bill
  • Must be emptied regularly and that can become tiring in the long run
  • Windows have to have to be closed when using a dehumidifier

How to Stop Condensation Forming On Windows Overnight?

How to Stop Condensation Forming On Windows Overnight

Waking up to see condensation on your window every morning might be a result of simply breathing. However, you can’t stop breathing, can you?

It’s not practical to reduce your oxygen intake; not an ideal solution, and nobody should experiment with that.

There are a few tips you can try out to get rid of the excess moisture in your motorhome, so let’s take a look.

First, try opening up your windows at night to improve air flow, as doing so will also help release warm, damp air. However, if there’s rain or you have colder-than-normal weather, you can opt for using curtains with thinner materials.

You can also use silver screens on your cab windows to provide insulation and act as a barrier between the windscreen and outside, so warm air doesn’t collide with the outer cold air and form condensation.

Alternatively, you can check for leaks in the roof and ensure there’s no crack in the floor either because these are avenues for extra water vapour to seep through.

Also, if you can, try re-insulating the walls of your motorhome because this will reduce the cost of heating while keeping it warm. Good insulation will determine how fast condensation occurs and how long it’ll take to dry.


It’s almost impossible to keep your motorhome condensation-free all year round because you’ll have to breathe, bathe, and, at some point, boil water for tea.

The build-up of moisture can cause improper ventilation, which leads to condensation. Installing solar panels in your motorhome sometimes creates holes that might allow moisture to pass through. When you notice signs of that, the best advice is to get it covered ASAP.

During summer, try investing in a dehumidifier in which water vapour can condense.

The best way to stop condensation in your motorhome is to maintain adequate airflow and use vented heaters. Plus, you’ll even improve your quality of living.


What should a damp meter read in a motorhome?

Ideally, the damp meter in your motorhome should read below 15% because that indicates zero moisture in the air. However, anything above 15% means you need to carry out a thorough condensation check.

Should you use a dehumidifier in a motorhome?

Yes, you should, as it’s one of the most effective ways to get rid of the water vapour present in your motorhome.

What should the humidity be in a motorhome?

For maximum comfort, the humidity percentage of your motorhome during winter and summer needs to be between 30% to 50%. Anything above these figures exposes you to water damage, rust, frost and mould.

Why is there so much moisture in my motorhome?

When warm air from outside enters your motorhome through the windows or any other openings and merges with the cold interior of your motorhome, moisture forms. So, excess moisture forms when it’s cold outside and warm inside. Try installing a vapor barrier.

3 thoughts on “How To Stop And Prevent Condensation And Moisture In Motorhomes & Campervans?

  1. How can I stop condensation forming when my motor home is kept in a storage site where there is no electricity available?

    1. If you are getting condensation when your motorhome is in storage it means it is leaking, when you are not using the motorhome there is no source of water unless it is leaking. Buy or borrow a damp meter and use it to find where the water is getting in, the wallboard near the leak will have high damp readings. You will need to locate the leak / leaks and get it sealed up. Depending on the contruction of your motorhome, there may be rotten timber which needs cutting out and replacing.

  2. How can I stop condensation in my motor home whilst it is kept in a storage yard with no electricity available?

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