condensation on windows

[Chad_Jen]

We don't normally go camping in the spring or fall when we need to run the furnace in the camper because our kids are in school, but we are this year. I noticed the other morning, after "camping" in the driveway with the furnace was running, there was condensation on all the windows. I didn't know if there was a way to prevent this or what those of you who go camping at this time of year do about it (if anything). We're laving on Saturday for six days so I have some time to prep if I need to. Thanks for the advice.

[GordonThree]

RV repair tech told me that having condensation on the windows means there is also condensation inside the walls, you just can't see it.

Condensation is a product of more moisture than the atmosphere can support, there's a bunch of variables behind it. Cracking the windows and roof vents NEVER worked for me, especially since I use my RV's kitchen a lot.

I purchased a Frigidaire 70 pint dehumidifier and leave it on if I'm at a CG with power, or run it occasionally if I'm bookdocking. It's amazing after running for a few days the gallons of water that I dump out. One of these days I'll drill a hole in the belly and run a drain hose for it.

[dclark1946]

Chad/Jen wrote:
Thanks to all for helping. We had virtually no condensation on the windows after cracking a couple windows and the roof vents. We stayed warm for the most part too.

That is all you should need to do based on our experience in cold weather camping. No need for a dehumidifier. We do get a little moisture on the windows when we use a catalytic heater (when dry camping) but we have both a window and a vent opened slightly. We do the same with an electric heater except we we don't usually have the window opened until we make coffee and run the bathroom vent fan on low to vent excessive moisture.

Dick

[TXiceman]

Running the gas furnace does not cause moisture in the RV. The heating by the furnace is a straight adiabatic heating and the number of grains in the air is unchanged.

The solution is to limit and control moisture in the RV. Keep a roof vent open about 1/2", maybe two open a bit and one window cracked open just a bit.

When cooking, run a vent fan to get the moisture out of the RV. Also, the open flame puts some moisture in the air.

When showering, open the roof vent nearest tot he shower 2" or 3" and when completed, run the vent fan for a minute or so. Also wipe down the shower with a squeegee to get the extra water out of the RV.

Next RV you get, order the Thermo pane or dual pane windows to reduce the condensation problem.

A dehumidifier is not really the answer. You can pretty much make your own part time dehumidifier by running an electric heater on low and run the A/C unit. This is all a dehumidifier does, but it used the hear from the condenser to heat the air.

Ken

[Margos_]

Yes, having the roof vents open will help. I'm looking into one of the small dehumidifer. Not sure which one yet.

[2oldman]

Specify dual pane windows on your next coach.

[PAAK]

Another trick that I have used is this. Since space is limited in a TT, get a coffee can and fill it with charcoal bricks, the charcoal will absorb the moisture and not take up space.

[Chad_Jen]

Thanks to all for helping. We had virtually no condensation on the windows after cracking a couple windows and the roof vents. We stayed warm for the most part too.

[myredracer]

Some more thoughts (JMHO):

Human bodies release moisture into the air of approx. (from respiration and evaporation) of around 2 pints to 2 gallons per day depending on activity level. Kids and pets will release moisture too. So even before you shower or cook inside, there's a lot of moisture that needs to be vented outside in cold weather.

The construction of a TT (and other RVs) is not conducive towards cold weather use. Homes require a vapor barrier on the interior side of a wall by code, but TTs have it on the exterior side in the form of an impermeable fiberglass or metal skin. Fiberglass sided TTs use open cell insulation (not sure if some use closed cell) so moisture can migrate to the exterior skin and condense. This will not hurt aluminum framing but I have to wonder if it can contribute to delamination or other problems. For wood framed TTs with fiberglass batt insulation, moisture condensing on the inside of the wall cavity against the metal skin will not be good and will contribute to rotting of the framing and subfloor.

The same situation of a vapor barrier on the wrong side occurs with the roof/ceiling assembly as the roofing membrane is impermeable. And the roof/ceiling cavity is not vented like in a house.

It's very important to vent the moisture out of your TT when camping in cold weather. Don't seal up openings in an effort to conserve heat. I would consider using a hygrometer to see what the relative humidity is inside. Humans like the RH to be between 20-60% but I've never seen recommendations for RVs (especially considering the reversed vapor barrier). I would think a dehumidifer is a good idea in winter.

I read about one person who was full-timing in Wa. near the coast in the winter where the humidity level is higher. He had water drops literally raining down on him from the ceiling throughout. At first he thought it was a leaking roof but it turned out to be too high a humidity level caused by a failure to open vents and sealing up openings to conserve heat.

[avoidcrowds]

I cook outside, which stops some of the condensation. But, I heat DW's tea water inside, we shower, and do dishes inside. I open the roof vent about an inch, and open the window next to my pillow about half an inch. This keeps condensation away.

If dry camping, dehumidifier won't have power, I imagine. Just keep roof vent and at least one window cracked, and you will likely be good.

[JBarca]

When we winter camp we do this:

When doing any cooking or dishes, crack a window near the stove open.
When showering, open the vent a good 1 to 2" to vent moisture out.
When sleeping, crack open a roof vent a good 1" to 2" inches. We do the one the farthest from the bed room.
During the day, leave the vent open as well, just may be able to close a little.
We use a dehumidifier
We do the shrink wrap on the windows.
Get a humidity meter to measure how good or bad it is.

If you are doing winter or cold weather camping in your 2 or 3 season camper you have to deal with moisture and keep it in check or it can over time start problems.

Small spaces, Single pane glass, aluminum window frames, no vapor barrier, no attic vents in the roof all add to the problem. While you cannot practically redo the way your camper is built, you can understand the moisture problem and compensate for them. Cool/cold weather camping can be fun. No bugs, fewer people, nice and peaceful.

Hope this helps

Good luck

John

[CavemanCharlie]

LynnandCarol wrote:
small dehumidifier @ lowes for about $40.

Where????? I've never seen one for less then $150. I can always use one in my house so if you have found them cheaper let me know.

[CavemanCharlie]

WolverineState wrote:
We were just camping here in Michigan the other weekend and had the same problem. Cold enough where we had the furnace on that created condesation on the windows and even the closed roof vents. The roof vent above our bed was dripping a small amount of water due to the condensation. We're adding a dehumidifier to our trailer for fall/spring camping. Look at the Eva Dry models on Amazon.

I would like to see how well this one works too.

http://www.amazon.com/Eva-Dry-Edv-2200-Eva-dry-Dehumidifier-Mid-Size/dp/B001QTW6KQ/ref=sr_1_4?ie=UTF...

[GilliedogKiwi]

WolverineState wrote:
We were just camping here in Michigan the other weekend and had the same problem. Cold enough where we had the furnace on that created condesation on the windows and even the closed roof vents. The roof vent above our bed was dripping a small amount of water due to the condensation. We're adding a dehumidifier to our trailer for fall/spring camping. Look at the Eva Dry models on Amazon.

They look nice and small - I wonder if anyone on the list has tried them? I look forward to any reviews.

[WolverineState]

We were just camping here in Michigan the other weekend and had the same problem. Cold enough where we had the furnace on that created condesation on the windows and even the closed roof vents. The roof vent above our bed was dripping a small amount of water due to the condensation. We're adding a dehumidifier to our trailer for fall/spring camping. Look at the Eva Dry models on Amazon.