Matt Johnson

How to Keep Moisture Out of your RV in the Winter

Author: Matt JohnsonPhotos/Graphics: Mike HawthornePublished: Jan 11, 2022Updated: Dec 13, 2023

Mold is a fungus that can grow in high humidity environments and cause health problems. This article will discuss ways to keep moisture out of your RV in the winter to prevent mold from growing.

Mold in your RV? Moisture is the culprit.

So you pulled your camper out of storage to take it on a glamping excursion and noticed you have mold growing in various places within the trailer.

What is this from? You cleaned the camper before putting it in storage for the winter; how can this be?

Chances are, your RV provided the perfect environment for mold to grow. You might’ve had a leak, the humidity could’ve been high for the past few months, and it was left unattended. This is the perfect environment to grow mold.

This is a problem, but how do you avoid it?

Before we get into the details of how you keep moisture out of your RV in the winter, we need to know more about how mold grows.

What is mold, and why should you care about it.

Mold is a fungus that grows with minimal intervention and takes over our spaces. In your case, your RV.

Mold spores need three things to grow: moisture, a food source, and the right temperature. That’s why it’s essential to keep the moisture levels down in your RV during the winter months – so you can avoid having a mold problem.

When the humidity levels are high in your RV, the mold will feed on whatever it can find. Anything from wood, carpet, fabric, and even leather!

The combination of cold air, moist air, and cold surfaces give the mold and mildew the ideal environment to thrive.

The way you take care of a mold issue is different for each material or surface, but the best thing you can do is prevent it altogether by keeping moisture out of your RV. So when you’re looking at how to keep moisture out of rv in winter weather, this should be your driving factor.

Ways to get rid of excess moisture in your RV.

You can do a few things to keep the moisture at bay, depending on whether you’re using your RV or not will dictate which methods you need to use.

When your RV is in storage for the winter.

While you might not be able to do much about a cold RV in cold weather when it’s in storage, you can do a couple of things to prevent moisture buildup. So if you’re wondering how to keep moisture out of RV in winter weather, this is how.

Here are a few ways to keep trapped moisture out of your RV while it’s in storage or not in use.

DampRid is Great for Campers
  • Fix any leaks and seal off any cracks. If your camper allows water in, you’re creating a breeding ground for mold. Use caulking and weatherstripping to seal off any potential leaking areas in your trailer.
  • Install a moisture barrier. If your RV is in winter storage for a few months, then you might want to invest in a temporary moisture barrier. Since most RVs don’t have double-pane windows (they usually have single pane windows) and there’s no way to circulate air when it’s in storage, you have to do what you can to keep the moisture out. You can install a moisture barrier on your walls or windows to reduce condensation.
  • Place moisture-absorbent packs throughout your RV. These are handy, easy to place and do a great job keeping moisture levels at a minimum. Damp Rid is probably the most common brand of moisture absorbers, but many are on the market.
  • Close RV windows and open cabinet doors during cold weather. This might sound obvious, but when your RV is in storage, ensure the RV windows are closed and leave the cabinet doors open. We’ve seen many RV owners accidentally leave their RV windows cracked when it’s in storage, and this allows colder air to enter your camper, where condensation forms. Keeping your cabinet doors open prevents the air from stagnating and keeps the air moving in an area where moisture is typically found.

When using your RV.

If you’re actively staying in the RV, whether on the weekends or even if you’re full-time, you’ll still want to remove moisture and keep the moisture out.

Ceiling Vent Fan Keeps Moisture out of RV
Photo courtesy of Pinterest.
  • Turn up the heat. By keeping the inside of your camper warm, the cold surfaces will heat up as well. This will prevent them from forming condensation on them. Avoid using your propane furnace and use the electric heater if you want to avoid moisture. Propane heaters can add around 1.6 pounds of moisture to your RV for every pound of propane burned with the propane furnace. Electric heaters don’t put off moist air; in fact, they produce dry heat. It’s an effective way to remove cold air while removing excess moisture.
  • Invest in a dehumidifier to remove RV condensation. In addition to using an electric heater, you’ll want to look into an electric dehumidifier. These come in various sizes, so you’d be sure to find one that works well in your RV. How they work is they draw in warm air and run it over refrigerated coils, which pulls the humidity from the air. They’re very effective and don’t cost much.
  • Push the moisture out with a window or ceiling vent. Use a vent with a fan to push the moisture out of your RV. The fan will remove water from your camper like your bathroom vent. You can also open up windows throughout your trailer and turn on some fans to keep the humidity down. All of these methods will let the humid air escape your RV.
  • Turn on your air conditioner to lower your indoor humidity. While this may seem counterintuitive in the winter, using your air conditioning unit is a quick way to lower the relative humidity and indoor temperatures inside your RV. Of course, your inside air temperature will drop a bit, but you don’t want it to keep running. Run it just enough to balance out that warmer air and moisture from a hot shower.

Prevent condensation and moist air from building up in the first place.

Now that you know what to do to get rid of excess moisture let’s highlight some tips for preventing it from building up in the first place.

  • Limit hot showers. We all love a long hot shower, especially on a cold day. But with the long shower comes warm air and moisture. Of course, you’ll have some moisture build-up with a hot shower, but you want to prevent too much moisture from building up. Limit the hot showers as much as you can. Use the roof vents in the bathroom while you’re in the shower as well. This will prevent water vapor from building up and will also help to keep the air circulating in your bathroom.
  • Do some outdoor cooking with your Instant Pot and other appliances. I’ve never had a meal from an Instant Pot I didn’t like, but they’re also known for producing a lot of condensation inside whatever space they’re used in – especially small enclosed spaces. If you can, try to use appliances like this outside. If you really have to use them inside, make sure you have adequate air circulation by using vent fans.

Still have questions?

We’re always getting questions about camping and glamping; however, this time of year usually brings questions about moisture, mold, and mildew. Here’s some of the most commonly asked questions we’ve received.

Why does walls in cupboard RV get moisture?

This is due to the humidity and temperature difference between the inside of the cabinet and the outside air. This happens more when an RV is packed away in storage, but it can also happen while you’re occupying the camper. The best way to defeat this is to leave the cabinet doors open. This allows the humidity and temperature to balance out.

Does DampRid work in RV?

Absolutely! We’ve used it for years. The one thing we’d caution is that it does require air circulation. When your travel trailer is in storage, you typically don’t have moving air, so Damp Rid is not as effective. However, it still works to some degree so we recommend putting a few throughout your camper.

Do you need a dehumidifier for your RV in winter?

You might not need one, depending on how you have your thermostat set, but we definitely recommend one. If you live in an area with high humidity and colder temperatures, you will benefit the most from having an RV dehumidifier.

How do I prepare my RV for long-term storage?

The best way to prepare your RV is to seal it up tight. With the RV slide-outs in, ensure all windows are closed, cabinets are open, and vents are closed, and place a few moisture absorbers throughout your camper. This will usually do the trick.

With cold air comes mold growth and musty odor.

These are just a few ways to keep the moisture out of your RV in the winter. It’s essential to use them because mold can be a severe health hazard and could damage your property if not taken care of quickly.

To prevent mold and mildew from building up, it’s essential to remove moisture whenever possible. Whether that requires using an RV dehumidifier, using vent fans, or any other method we discussed to prevent condensation, it’ll go a long way in keeping your camper and your health in great shape.


Matt Johnson

Senior Content Writer

Matt is an experienced camper and glamping enthusiast with a Master's degree in Wildlife Science from Texas A&M University. Authoring posts for GlamperGear, he shares his wealth of knowledge on picturesque campsites, luxurious accommodations, and the best gear for outdoor adventures. His passion for nature and knack for comfort in the wilderness make him an expert guide for your next camping endeavor.

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