How to Keep Moisture Out of Your RV to Minimize Condensation

The lightweight and versatile nature of RVs makes them easily prone to damage from the elements, and moisture is one of the most destructive culprits.

Moisture seeps in through unknown cracks and collects as condensation on windows and walls

Left to its own devices, moisture will cause mold and mildew as well as corrosion and wood rot.

Moisture and condensation can bring about long-term damage to your vehicle as well as health problems to those traveling in it.

Although moisture from the environment is not entirely avoidable, there are steps that owners can take to prevent or minimize the condensation and humidity from building up while winter camping or while it’s in storage.

Understanding where they come from and how they behave is the key to reducing moisture and condensation in a travel trailer or motorhome.

This article will teach you all you need to know about moisture and condensation, from the causes and effects, to habits and gadgets you can use to keep moisture out of your RV. 

What Causes Condensation in an RV?

What Causes Condensation in an RV

To understand condensation, let’s begin with a bit of basic chemistry.

The amount of moisture in the air is one factor of the equation, while the temperature difference between your RV and the surrounding air is another. 

When the temperature of a surface is colder than that of the surrounding air, it reaches a saturation temperature, at which point a process opposite of evaporation occurs.

As it touches the surface, the air will no longer be able to hold its water, so the water will instead begin to stick to the surface as a liquid.

This is also known as the dew point, and it is what causes condensation to form. 

A dew point is most easily reached with materials that are thermally conductive. That is why RVs will usually collect condensation on surfaces such as:

  • Windows
  • Mirrors
  • Metal doors and trim

When left unattended, condensation may also begin to collect on the interior of the thin RV walls, creating soft spots or even holes in walls and floors. 

Condensation most commonly occurs in colder weather, when the interior of the RV is warmer than the temperature outside.

However, it can also happen in hot summer months when the AC is on high, as well as in humid climates where water sits heavy in the air. 

Moisture also accumulates in RVs through the water we bring into it. Common environmental factors include:

  • Steam from cooking or showering
  • Sitting water
  • Humidifiers

Regardless of what causes it, condensation requires the right combination of two factors — moisture in the air, and for the surfaces of your RV to be at a saturation temperature relative to the surrounding air.

The more we reduce these factors, the less likely it will be for damaging condensation to form. 

7 Tips To Reduce Humidity to Minimize Condensation In Your RV

You may not be able to control the weather, but you can control what goes on in your RV.

Condensation can be a pesky problem, but it is easily be kept under control through good water usage habits and a few simple gadgets.

Whether you’re preventing condensation or trying to get rid of it, the main focus should be reducing the amount of moisture that gets trapped in your RV. 

Let’s take a look at the best ways to reduce moisture in your RV while camping. 

1. Use Vent Fans to Remove Steam

Use Vent Fans to Remove Steam

Whether you’re cooking, showering, or doing the dishes, the steam that results from using hot water can quickly turn into condensation.

Luckily, RVs come with vent fans to pull steam out before it can collect. If the fan broken or want to buy new, then check our article about Best RV Roof Vent Fan.

Vent fans can be found on the ceiling, in bathrooms, and above the stove. Run them whenever you cook on the stove or use hot water to keep moisture from getting trapped inside. 

2. Open the Windows. 

One of the easiest ways to prevent condensation inside your RV is to open the windows. Doing so allows moisture to escape while allowing the drier outdoor air in.

This is especially useful to release steam when used in conjunction with vent fans, though it is generally helpful to crack a window a couple times a day whenever the temperature allows. 

3. Be Mindful of How You Cook

Cooking is one of the biggest causes of excess moisture getting trapped in RVs.

Not all cooking is the same though, and there are certain methods and practices that can help us enjoy homecooked meals without creating unwanted condensation.

Stovetop cooking will generally produce the most amount of moisture.

Use alternate methods whenever they are available, and be sure to use a lid as much as possible when you do choose to use your stove. 

Ovens create significantly less moisture than stoves because they are enclosed units that usually don’t cook foods heavy in liquids.

Similarly, pressure cookers and slow cookers are great devices that contain moisture while cooking.

Just be sure to allow the clouds of steam to escape by opening windows and running fans whenever you open the lid or release pressure. 

And if you really want to embrace the camping experience, there’s always the option of cooking outside. Grills, hot plates, and even campfires can be great ways to heat up your meals. 

4. Shower Outside or at Campsite Facilities

Next to cooking, showering is one of the biggest culprits when it comes to moisture and condensation in RVs.

Between the large amounts of water used in the process and the steam that may result from hot showers, it is common to find condensation sitting on mirrors and windows before we even finish. 

Having a shower in your RV can be wonderfully convenient, but it doesn’t necessarily have to be used when other options are available.

Showering outside on warm days or using campsite facilities whenever they’re available can make a big difference in how much moisture gets trapped in your RV. 

5. Dry Your Clothes Outside

Dry Your Clothes Outside

Whether you’re doing laundry by hand or drying towels and beach clothes, there’s a good chance you’ll find yourself hanging things to dry while traveling.

However, it’s easy to forget about the moisture created in the process.

Although we may not be able see it like we can see steam, wet clothes dry through the process of evaporation.

If we hang them inside, the moisture evaporates from the clothes just to get trapped in the RV. 

The easy solution is to simply hang your things to dry outside whenever the weather allows it.

There are even drying racks specifically designed to attach to an RV ladder. Alternately, air out your RV during and after drying by opening windows and using vent fans. 

6. Open Cabinet Doors

Condensation on windows and mirrors is easy to spot, but it is often overlooked when it collects in the dark corners of cabinets and closets.

Moisture in the RV can leak into these cubbies and get trapped, growing unwanted mold and mildew for weeks, months, or even years before ever being spotted. 

Mold and mildew are not only damaging to your RV, but they can cause some serious health issues as well.

We may not regularly see the mold growing in the back corner under the sink, for example, but it may cause symptoms like coughing, itchy eyes, and runny noses.

To keep even the deepest corners of your RV dry, prevent moisture from getting trapped in closed spaces by providing it an outlet.

Simply opening cabinet doors and drawers whenever you are in a humid climate or are airing out your RV can keep moisture in even the darkest cracks at bay. 

7. Air Out Your Mattresses

Just as cabinets and other enclosed spaces can trap moisture, the undersides of mattresses frequently go overlooked.

When left unattended, mold and mildew can grow and spread into and across your mattress, potentially affecting your health and, with time, ruining the entire mattress. 

Airing mattresses out regularly is the key to keeping moisture from getting trapped.

This can be done by occasionally standing the mattress on its side when not in use, and by increasing air circulation throughout the cabin. 

It’s also possible to reduce the chances of moisture getting trapped under your mattress.

One consideration is the material of your mattress, with foam mattresses attracting the most moisture.

They are porous and often contained in a polyurethane casing, harboring moisture and allowing no way for it to be released. 

Even though it’s possible to treat the surface of the mattress, mold and mildew sink deep into the material once they begin to grow and you’ll be forced to get a new one.

An innerspring mattress, on the other hand, is made of a more breathable material and allows for more airflow, reducing the chances of mold and mildew from growing. 

Regardless of the type of mattress that you have, it’s also a good idea to vent the underside of your mattress.

Use a vented mattress underlay that allows airflow, or, if you’re crafty, create a slated system for the mattress to sit on. 

Handy Accessories That Reduce Moisture and Condensation Inside Your RV

Moisture is persistent, and it sometimes collects faster and more heavily than even the most conscious and careful RVers can keep up with.

Luckily, the following accessories are excellent tools to help us in the battle against moisture and condensation.

1. Moisture Absorbers

Moisture absorbers are relatively cheap, do a great job at capturing moisture hanging in the air, and require very little maintenance.

Simply hang or place them in closets and corners and let the moisture absorbing beads do their magic.

You’ll see that they can no longer hold moisture when all of the beads have turned to liquid, at which point you just replace the unit with a new one. 

2. Dehumidifier 

RV Dehumidifier 

Dehumidifiers work great because they actively draw moisture out of the air. The most common type of dehumidifier is refrigerant based.

It contains chilled coils within the unit that reach a dew point at which moisture from the air collects on the coils as condensation.

This condensation then drips down into a receptacle that can later be emptied. Dehumidifiers work best in larger, open spaces with some airflow. 

3. Fans

Fans increase air circulation and help to keep the interior of the RV cabin cool. Use them alongside vent fans to direct steam out of the RV and to dry out any left-over moisture. 

4. Space Heaters

Space Heaters

Propane furnaces bring a lot of moisture into the RV and are best used as little as possible.

Of course, you’ll need some form of heat source when RVing in colder months, so space heaters become a great solution.

Space heaters run on electricity and thus don’t add any additional moisture to the RV.

They come in a variety of sizes to accommodate the size of your RV, and it doesn’t take long for one to warm up the interior. 

However, keep in mind that space heaters are only useful for enclosed spaces.

If you are living or camping in your RV in cold winter months and need to keep the pipes and wires in the underbelly from freezing, you’ll have to run the propane furnace to do so. 

5. Window Insulation

Windows are one of the first places that collect condensation in RVs because glass tends to chill faster than most other surfaces.

Adding window insulation can keep them at a higher temperature, in turn preventing condensation from building up. 

How Do I Keep Condensation Out of My RV While It’s in Storage?

Condensation is primarily a problem when the RV is in use because of the potential temperature differences between the RV and the exterior, as well as the moisture that we contribute through daily use.

However, it is possible for moisture to collect in an unused RV, particularly if it is stored in a wet or humid climate. 

Moisture that may be present in an RV while it’s in storage may collect enough to do damage when there is a lack of airflow.

Opening small spaces such as cabinet doors and drawers can help the entire RV “breathe”.

In addition, placing moisture absorbing packs throughout the RV can help to reduce the overall amount of moisture in the vehicle.

Last Updated on by Aaron Richardson

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