If you own an RV, you have either had or heard of others having problems with condensation, which might leave you wondering what causes this, and how can it be prevented? We have investigated this issue so you can enjoy your camper without worry.
Condensation can form on the hard surfaces of the interior of the RV, and can ultimately cause mold, wood rot, and corrosion if not kept under control. To prevent condensation from forming in your RV, you should do the following:
- Use a moisture absorber.
- Open a window or vent.
- Increase the temperature in the RV.
- Improve window insulation.
- Use an extractor or vent fans.
- Dry clothes outdoor.
- Cook outside whenever possible, if not cover pots and pans.
- Use campground shower facilities.
- Keep track of your humidity level with a hydrometer.
- Use a dehumidifier or two, depending on the size of your rig.
We researched this subject in-depth and have outlined these methods in more detail below.
What is condensation
Condensation is caused when you are camping in an area with high humidity or in colder temperatures. It occurs when water in gas form changes back into liquid.
Essentially, air can carry a certain amount of water molecules in the form of gas - which we can sometimes see as steam or vapor. Other times, we can't see the water in the air at all.
Just how much the air can carry depends on the temperature. The warmer the air, the more water it can hold in gas form - without any liquid showing up. We call that humidity. When it's warm, the air is more humid - which means it holds more water in gas form.
People excrete water into the environment. Not just through sweating but in our breath as well.
When you have people breathing and living within the confines of an enclosed RV, that humidity can quickly build up. Meeting cold surfaces within the RV, it can turn into liquid water.
That's condensation for you.
Why is condensation a problem in an RV?
Condensation means liquid water on surfaces.
And that's bad news.
Water can cause materials to rot and deteriorate. You really want to keep everything dry in order to have your RV last for longer (read here to find out how much RVs can actually last!)
It can also cause mold. Microscopic fungal spores are everywhere. If they find a wet-enough surface, they will hatch into an actual mold. Not only does mold rot your RV, but it's also bad for your health.
10 Ways to Prevent Condensation in your RV
1. Use a Moisture Absorber
Moisture Absorbers are a container of crystals that remove excess moisture from the air. They are most effective in warmer climates and highly recommended if you are going to be anywhere in the Southeast. There are multiple products on the market that are ready to use, such as DampRid, or you can make your own out of rock salt, calcium chloride, silica gel, or moisture absorber crystals.
2. Open a Window or Vent
Opening a window or vent works during warm weather months to keep air circulating and warm. As dry outdoor air mixes with the indoor air, the moisture will decrease, slowing the formation of condensation. This is not recommended in colder weather as it will cause your warm air to cool, having the opposite effect, and creating condensation.
3. Turn Up the Heat
You can turn up the temperature in the RV so that the air remains warm and any humidity remains in gaseous form. The higher the temperature, the less likely it is that condensation will be able to form.
4. Improve Window Insulation
RV windows are single pane, and notorious for being poorly insulated. You can either replace them with dual-pane acrylic windows, or use a do-it-yourself window insulation solution, such as Reflectix, or shrink plastic. This will also help to hold the heat in and the cold air out when the temperature drops.
5. Use an Extractor or Vent Fans
Make sure that you switch on your exhaust or vent fans when you are cooking, washing dishes, or taking a shower. These fans help to expel the moist air from your RV into the outdoors.
6. Go to the Laundromat
Wash your laundry at a separate laundry facility, or at the very least, dry your clothes outside. As your clothes dry, the water evaporates from the fibers and turns into vapor, filling the air. If you string a clothesline between two trees or posts and hang your laundry out there to dry in the sunshine, you will keep this moisture outside.
7. Cook outside
Cooking is one of the largest producers of water vapor in your RV. If it is possible, cook outside on your portable grill or campfire. If this is not an option, then try altering your cooking methods to minimize the use of water. Try to avoid boiling or steaming food. Cover all pots and pans when cooking so any vapor is collected in the pan.
8. Use the Campground Shower Facilities
Using public campground facilities is another way to keep the humidity down. Plus, you will save on water used with the added bonus of being able to take a long, hot shower in a reasonably sized space, instead of crammed into your RV shower. It’s a win-win situation!
9. Get a Hydrometer
A hydrometer will tell you how high the humidity is in your RV. Some dehydrators come with them built-in, but you can always purchase a small inexpensive one that will do the job. It is important to know what the humidity should be depending on the temperature outside. For every 10 degrees Fahrenheit it is outside, you need to decrease the humidity by 5%. Examples of Optimal Humidity in an RV
| Temperature Indoors | Optimal Humidity |
| 20 degrees F | 35% |
| 10 degrees F | 30% |
| 0 degrees F | 25% |
| -10 degrees F | 20% |
10. Dehumidifiers are Your Friend
Dehumidifiers are similar to Moisture absorbers, in that they help remove water from the air. They draw air over cold coils, condensing out its moisture, before passing the air over warm coils and back into the room.
The difference is that they require power, but are much more effective especially when the temperature gets colder. You may need more than one depending on the size of your RV.
What Is the Best Kind of Dehydrator for an RV?
There are three kinds of dehydrators available. The kind that you need is dependent on the size of your RV, as well as the intensity of the humidity that you are combating.
Residential Dehumidifiers
Air Dryers are best for very small campers and when the temperatures are cooler, as they use convection to heat the nearby air past the dew point. The hot dry air then rises and is replaced with the cool, wet, air, which undergoes the same treatment.
Investing in a dehumidifier for your RV is a great decision if you have condensation problems. It will
- Help keep your RV safe from rot, prolonging its life.
- Keep you and your family safe from mold.
- Make the RV more pleasant to be in.
The Pro Breeze Electric Mini dehumidifier is a great choice for RV's. Portable and small, it's powerful and easy to operate.
Commercial-Grade Dehumidifiers
These dehumidifiers usually use a massive compressor to chill coils inside them, and a fan to pull air from the room across those coils. As the air cools, the water drops out of it and is collected in a containment basin which will need to be drained.
Compressor-based dehumidifiers are the most effective at removing moisture from the air but use electricity to do so. They're also very expensive. These are relatively massive machines that are usually not a good fit for RVers - definitely not when you're living in the RV!
If you do have a major condensation or mold problem, at home or in your RV, then it's worth knowing them. This is what a compressor-based dehumidifier looks like.
Dissican dehumidifiers
Dissican dehumidifiers use absorbent silica gel beads to pull moisture from the air. They don’t use any electricity, to use, but they do need to be plugged in to dry out the silica gel beads.
This is best done at home after your trip is completed, as the drying process releases the moisture back into the air. These work better in smaller spaces, so you may need two or more if you have a larger camper.
Try these bags and see if they're enough to solve the condensation problems in your RV.
Click here to buy this product on Amazon.
What to Do If You Find Condensation in Your RV
If you are in a situation where you find beads of condensation forming, then you need to take action immediately to eliminate it so mold and mildew do not take hold.
- Wipe down all surfaces where you can see the condensation. You will want to dry your counters, stovetop, walls, windows, tabletops, and appliances.
- If it is warm outside, open the windows and run a fan to circulate the moist air and dry any damp surfaces.
- Open cabinets and closets so that the air can circulate. These overlooked areas are ideal places for mold to form as they are hard to see for air to reach.
- Make sure that your dehydrators are working.
- Replace your moisture absorber.
Stay Vigilant and Relax!
While condensation can cause a lot of problems, as long as you follow the steps outlined above, you should not have any issues. Now that you know what to do and what to look for, you can just enjoy your RV!
Be sure to check out these other useful guides -
RV Water Leak? Here's What To Do
How To Choose An RV Generator (The Complete Guide)
49 RV Maintenance Tips (That Will Save You Time, Money and Heartache)