It’s no secret that excess moisture inside your RV is bad. However, when most people think about water getting into their camper, they think about issues with the roof or walls, or misbehaving appliances like your RV AC dripping water inside. We tend to forget about the moisture in the air – humidity.
Excess humidity can cause damage, just like a roof leak. This is why preventative moisture and condensation management in an RV is important. In this article, we’ll review everything you need to know about prevention, from cracking a window to using the best dehumidifier for an RV to keep humidity at bay.
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ToggleHow Does Humidity Get Inside an RV?
There are many ways humidity can enter your RV. For starters, humidity is caused by breathing, so you’ll never stop it completely. It occurs when cooking; moisture is expelled from food and into the air. It accumulates from showers, which can be amplified with more people staying inside the camper.
If you live in a humid environment like Florida, you’ll likely have more problems than someone living in Montana. The way the RV is constructed also plays a factor. RVs with poor insulation actually do a better job of getting rid of moisture due to better circulation. You’ll never stop all moisture from entering your RV, so you’ll need to take steps to monitor and remove it.
Remember that you don’t want to remove all moisture from the air; your goal should be to have a humidity level between 30% and 50%.
Why Is Humidity Inside An RV a Problem?
There are many reasons to remove excess moisture from the air in your RV. It can make you feel hot and sticky in the summer and even make breathing harder. If the moisture gets trapped behind the walls and ceiling, it can lead to delamination, mold, and mildew. Mold and mildew are bigger issues while your RV is in storage, where your camper can sit for several months, usually covered.
Spring and summer are typically the most humid seasons because warm air holds more moisture, but humidity can also cause problems in the winter. Condensation can occur, resulting in water droplets on the windows, doors, and countertops.
Preventing and Getting Rid of Humidity
There are many ways to remove humidity inside an RV. The biggest helper is your air conditioning unit. Humidity is made worse by a lack of circulation, and your air conditioner does a great job of circulating air throughout the RV. However, you can’t always rely on this alone. Here are some other helpful strategies:
- Open a roof vent to let moisture escape when showering.
- Crack the closest window nearby when cooking.
- Use your vent fan to circulate air throughout the RV when weather permits.
- Leave windows open overnight when conditions permit.
- Supplement your RV air conditioner with one of the best dehumidifiers for RVs.
Let’s look further into this final option.
Types of RV Dehumidifiers
The two main styles of electric dehumidifiers for RVs are compressor and desiccant. The compressor-style pulls air through a filter and passes it over a set of cooling coils, which collect water as the air condenses. On the other hand, desiccant dehumidifiers pull air in and push it through a rotating wheel, which contains materials used for drying air, such as “silica.”
Let’s look at some of the pros and cons of each type:
Pros | Cons | |
Compressor | Cost Effective Very Efficient | Noisy Not Effective in Cold Temps |
Desiccant | Quiet Works Great in Cold/Warm Temps | High Power Consumption More Expensive |
Here are three of our top-selling electric RV dehumidifiers:
There are also non-electric desiccant-style dehumidifiers. These don’t require a power source, which makes them great for storage or everyday use since they don’t steal power from other appliances or take up floor/storage space. However, these trailer dehumidifiers must be replaced periodically as they are not reusable.
Do I Need a Dehumidifier for RV in Storage?
Yes, a dehumidifier for a camper is very important while it’s in storage, as the chances of mold and mildew buildup are higher. A lack of circulation usually causes this due to an RV cover blocking the vents. Cracking a window or vent while in storage is smart, but you’d still want to use a dehumidifier while sitting for extended periods.
If you can access shore power in storage, you can use an electric dehumidifier. Otherwise, you’d need to use a non-electric desiccant dehumidifier, also sometimes known as a moisture absorber.
Here are some of our picks for the best moisture absorber for RV use:
- Camco Moisture Absorber 5 lb. Bucket
- Camco Hanging Moisture Absorber, 2-pack
- HUMYDRY Premium Moisture Absorber, 15.9 oz.
Choosing the Best RV Dehumidifier
Size is the most important factor when selecting a dehumidifier for RV living. This includes the size of the unit and the amount of square footage it’s rated for. Let’s look closer at size/square footage rating and other factors to choose the best dehumidifier for a travel trailer or any other RV type.
Size and Square Footage Rating
If you choose a dehumidifier that is too small, it will run constantly and struggle to regulate humidity levels. If you choose a unit that is too large, it can take up more floor space and have higher wattage requirements. Although an oversized dehumidifier is better than a small dehumidifier for RVs, it’s best to get the right size.
You can find the right size by measuring your RV’s interior length and width to get the square footage. For example, if your RV is 30’ long x 9’ wide, you must account for 270 ft². Therefore, a unit rated for 300 ft² would be the perfect choice.
Tank Size
Tank size is also important to consider when selecting dehumidifiers for campers. The smaller the tank, the more frequently you must empty it. However, a larger tank means the unit takes up more space.
If you plan to leave the unit running for an extended period, you’ll want an RV dehumidifier with a drain hose so it does not shut off when the tank is full. Most accept a standard garden hose, which you can route to the nearest sink, allowing the dehumidifier to drain into your RV’s gray water holding tank. As the drains are gravity-fed, you must place the dehumidifier on a counter above the sink. Leave the waste valve open to prevent overfilling your gray tank.
You could also drill a hole in your floor if you don’t want to set it on the counter, but the former is preferred. If you live in an area with cold temperatures below freezing, consider a non-electric dehumidifier to prevent water from freezing in the tank and lines.
Power Source
Electric dehumidifiers require an external power source, usually 120VAC or 12VDC. If you spend most of your time at the campsite hooked up to shore power, 120VAC is your best option. However, if you camp off-grid without access to shore power, you’d want to consider a 12v dehumidifier for RV use.
If neither power source is available, don’t worry—there are still plenty of power-free desiccants to choose from.
You’ll never eliminate all the humidity inside your RV, nor will you want to. The goal is simply to monitor and control it. Some things you already have that can help with this like opening a window or running the vent fan, but they should also be supplemented with a dehumidifier.
Here are a few more resources to help you keep your RV at a comfortable temperature:
- How To Keep an RV Cool Without AC
- This Simple Tool Will Improve the Performance of Your RV Air Conditioner
- How To Stay Cool While Camping in the Heat
We hope you found this article helpful. Let us know in the comments below about your experiences with humidity in an RV.