Tuesday, October 3, 2023


Get a serious grip on RV condensation

By Jim Twamley

Dealing with condensation is a fact of RV life. Moisture is the RV’s worst enemy so you need to be aggressive in preventing it from causing damage.

Most often condensation will form on the windows of your RV during the night when you’re asleep. As you breathe, you exhale moisture into the air. When it’s cold outside RVers tend to close all the windows and vents, trapping moisture vapor inside the RV. The airborne moisture finds its way to the windows and forms a condensation of water droplets.

Our motorhome has dual pane windows everywhere except the windshield. No condensation forms on the dual pane windows but collects on the windshield instead. If you allow the condensation to remain on the window it will run down and pool on your dash. I normally use a towel to remove this excess moisture. I prefer microfiber towels because they have superior absorbent qualities.

Simply run the towel across the glass and you’re done. The best thing about these towels is they don’t leave streaks. Microfiber towels are great for RVs and can be purchased at hardware stores, RV parts stores, on Amazon.com, and warehouse stores like Costco. I buy mine at Costco because they have high-quality towels at a great price.

Don’t forget that venting your RV helps remove excess moisture, especially when cooking and showering. I really appreciate the Fan-Tastic vents we’ve had in our RVs over the years. They quickly remove odors and moisture from your RV. When you store your RV over the winter it’s a good idea to use a dehumidifier.



0 0 votes
Article Rating
Subscribe to comments
Notify of

This site uses Akismet to reduce spam. Learn how your comment data is processed.

Inline Feedbacks
View all comments
Gloria Sluder
3 years ago

I put cotton towels at the bottom of windshield to collect moisture. In the morning we set a cooling fan on dash and keep moving it till everything is dry. Sun dries the towels during the day. Wash towels after cold snap.

3 years ago

A 5KW diesel-fueled air heater proved to be the best answer for our truck camper. The installed LP furnace also recirculates interior air, without adding combustion-induced water vapor (unlike catalytic or ceramic-burner LP space heaters) but it is severely wasteful of fuel and battery power.

The diesel heater has two air circulation systems: the combustion air intake and exhaust are vented to the outside; the recirculating heated air is confined inside. It actually has a drying effect on the interior air. Efficiency of the heater is very high both in fuel use and battery power. Our single Group 27 deep cycle battery will run a 5KW heater all day/night without problem. A 1 gallon diesel fuel jug runs the heater at least two days.

An added bonus is the dry heat output is sufficient to leave the roof vent partly open to exhaust water vapor caused by cooking and breathing. Our single-pane windows simply do NOT collect condensation when running the diesel heater, nor do we get wet-mold patches behind cushions or under the cabover mattress.

3 years ago
Reply to  Gray

@Gray: Forgot to mention now you can use them Microfibre cloths for drying the RV and or car… No more fogged up dripping windows! 🙂

3 years ago

Do yourself a favor… Dump the LP heater OR if you have the room? Just add the necessary # of Diesel heaters. Problem solved. If your lucky enough to just be able to add them. switch as needed. as they will not promote condensation. in fact many people claim they make the air dry. (when in a dry climate). and if you must make it rain in your RV? go ahead and fire up the rain machine. ie the LP furnace. If you dont have the room? Switch the furnace out for the Diesel heaters they are small and robust. they have been around so long their darn near bullet proof. I did it in my 42′ 5th wheel. it had a 27K LP furnace. now I have dual 5Kw Diesel heaters. I can use 1 or both. if one fails? I’ll fall back on the 2nd one. Although I dont expect any failure anytime soon. Plus an added bonus? fuel for fuel? Diesel is much more efficient and cheaper than LP. my 2 cents. -Sam feel free to reach out to me if you have any questions. Mail4Sam@gmail.com -Sam

3 years ago

We don’t get the tip on microfiber towels. We’d never use the word absorbent and microfiber in the same sentence – they’re just not very absorbent – at last the ones we’ve used.

The kids gave us a colourful Costco pack for Christmas a few years back and the only use we’ve ever found for them is cleaning the screens on computers & TV’s.

A good big well used cotton towel does the trick for us – can’t beat them and everyone has some around.

3 years ago

We winter camp often. We always have both roof vents open about 1/4 inch and the same for at least 1 window to create cross ventilation, a small electric fan on the dash and a dehumidifier. I am always amazed at how much water is collected in the dehumidifier.

Abe Loughin
3 years ago

We like our bedroom much cooler than the rest of the RV so we run the bedroom air-conditioning even in cooler weather. It takes out so much humidity we sometimes need to add moisture to keep sinuses from drying out too much.

3 years ago

It’s simple, don’t fully close the vent above the bed at night and keep all vents open whenever possible. That lets some heat escape which is good because it carries moisture with it but it makes little difference in the amount of propane used.

Debra Rohm
3 years ago

We were having a condensation issue in our Motorhome and the dehumidifier wasn’t doing a good enough job to alleviate it. I bought a DAVIS AIR DRYR, plugged it in and we haven’t had a drop of condensation since! I bought it on-line from Wal-Mart for about $60.00

3 years ago
Reply to  Debra Rohm

Good tip Debra. We’ll be checking out this product.

Sign up for the

RVtravel Newsletter

Sign up and receive 3 FREE RV Checklists: Set-Up, Take-Down and Packing List.