Sunday, October 2, 2022


Prevent mold with these simple tricks to cut down humidity inside your RV

Ah, winter. It’s so cozy and warm when you’re cuddled up inside your RV, especially when the outside temps are frigid. Well, that cozy feeling is sure to cool when you begin to notice water droplets forming on the inside of your RV windows. That’s excess humidity and it is not your friend! When the warm, moist air from inside your rig hits the cold window glass, moisture forms. If that moisture builds up, the water droplets join together to form little rivers of wetness that will run down into the windowsill and from there into the wall. If left to continue, it’s a good bet mold will develop. Nobody wants that!

Here are simple RV hacks and tricks to help cut down on the humidity inside your RV this winter:


  • Don’t use the cooktop. Avoid cooking on the RV’s stovetop. Or, if you absolutely must cook on the stovetop, be sure to use the exhaust fan on its highest speed. Cover foods as they cook, as much as possible, to avoid steam from escaping directly into the RV’s interior.
  • Microwave. Alternatives to stovetop cooking? Use the microwave along with the vent. Once food is removed, quickly close the microwave rather than let the steam escape into the galley.
  • Pressure-type cooker. Another great alternative is to use an instant pot pressure-type cooker. Not only will your meals cook faster, but by releasing the pressure outside, you’ll keep the extra humidity out of the RV.
  • Get outside. Cook outside as much as possible. Use your gas grill or campfire to heat delicious meals without adding more humidity to the inside air.
  • Convection cooking. If you have a convection oven, use it instead of the propane oven which can produce steam.


  • Electric is best. Because propane produces humidity, it’s better to use an electric heater to warm your RV’s interior. If your RV features a fireplace, use it instead of the furnace. The same goes for a heat pump, if temperatures permit.
  • Small space heat sources. Consider using small, ceramic or infrared heaters to warm only the spaces where family members are, rather than attempting to heat bedrooms, toy hauler garage, etc., especially if you spend most of your time in other spaces within the RV.
  • Insulation. Make sure you’ve taken proper precautions for insulating your rig so that drafts are not an issue. It will help you stay warmer.
  • Dress for success. Consider dressing in layers so that you can keep comfortable even in cooler indoor temperatures.

Other considerations

  • Shortened showers. Hot showers put lots of excess humidity into your RV’s interior. Consider using the campground showers, if available. If you do shower inside your RV, keep it brief. Run the exhaust fans and crack open a window to help release the extra moisture to the outside.
  • Use the campground’s dryer. Resist the urge to dry clothing inside your RV. Use the campground’s laundry facility even if your rig has a clothes dryer.
  • Air circulation. Some folks swear by running a fan with one window opened slightly. We haven’t tried it, but proponents claim that the fan helps circulate the air and helps humid air escape more readily.
  • Track humidity levels. Purchase an indoor hygrometer like this one to keep track of the humidity inside your RV. If levels creep up past 40 percent you need more remediation.

Dehumidifier choices

  • Electric dehumidifier. A dehumidifier will draw moisture from the air and collect it. Dehumidifiers come in a wide variety of sizes and configurations. Before you buy, make sure the unit will fit inside your RV without hindering movement in the already confined space. Many RVers place their dehumidifiers right inside their shower pan. That way, the moisture that collects can simply run down the shower drain. This means you’ll need to move the dehumidifier every time someone wants to take a shower, so you’ll need to decide if that’s the best choice for you. Here’s a top-rated model perfect for RVs.
  • Alternatives. Damp Rid is another option for RVs that don’t require a dehumidifier. Damp Rid and similar products remove excess moisture from the air – though not in the amounts that an electric dehumidifier can. Here are some top picks to choose from.

As with most things related to RVing, some winter humidity preventive measures can help keep you happily on the road. If you have additional ideas to try, please let us know!



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Diane Mc
9 months ago

Wow. We are lucky. Never have had this issue. We have a 20 yr old Dutchstar w/dual pane windows. I take long hot showers. Use washer and dryer. I did ask my husband about keeping the weep holes free of debris. He said “that’s a good idea”…😂…20 yrs later. Although we had our coach reskinned & painted at Newmar 4 yrs ago so all the windows were removed & reinstalled. So now we are only 4 yrs behind. 😬. But so far hasn’t affected us humidity wise.

9 months ago

So many things on the internet written by people whose obviously don’t do the research. Rv furnaces do not put water vapor in the air. They are a closed system. Also a propane fireplace that is unvented will put a tremendous amount of water vapor in the air.

9 months ago
Reply to  bob

You are right. Only an open propane flame emits water vapor into the air. Use electric heat to supplement the furnace heat. Sorry for the confusion. Stay warm out there!

9 months ago

Please make sure your window “weep holes” are not plugged! I use compressed air thru a 1/4″ diameter copper tube once a year to keep them free of debris. Condensation will drip into your coaches wall if these slits are clogged.

9 months ago
Reply to  Dennis

Great tip, Dennis. Thanks!

9 months ago

Deep South, 100% humidity. I use a portable dehumidifier when the RV is not in use.

9 months ago

Propane does give off water when it burns. However, the admonition against using your propane furnace is totally off base. If the water vapor from your propane furnace is adding to the humidity levels in your RV, you have a very serious problem.

The exhaust (including the water vapor) from your furnace should never be inside your RV. It should exhaust directly outside and not be an issue.

Scott R. Ellis
9 months ago
Reply to  Tom

Thank you. This is an incredibly common misconception.

9 months ago

Good piece. But I’m curious about the 40% humidity target. Where did that come from? I assume you know that 40% humidity is VERY dry air, which is rarely seen in most homes. Particularly in the NW and SE, it’s very unlikely that any means could keep the air in an RV below that figure. I would think somewhere around 60-70% would be a more realistic target…

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