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Condensation In TT on Cold Mornings

herbhofmann
Explorer
Explorer
My DW and I went on our first October camping trip and first night out when it was cold enough to get condensation inside the TT.

Question: What is the best way to prevent this? Not only the windows were wet, but also along the aluminum framing. Our first TT was Stick and Tin (and old) so we never camped this late in the year.

My thinking is to keep the trailer a bit warmer at night (DW likes it COLD) and keep the vents open (got Maxairs on order). What do ya'll think?
Herb & Liz
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27 REPLIES 27

The_Dung_Beetle
Explorer
Explorer
We also live in the PNW.. land of mold and mildew...lol We have been trying to educate ourselves on the absolute best way to winterize our 20' TT. It's just not this damp where we came from originally. We've read and read... and READ. Had no problem with doing the RV antifreeze part etc, removed all food, candles etc..but still have some humidity concerns.

We found a good sized home dehumidifier on Craig's last summer, and set it up today. It's been raining hard off and on today - soggy soggy.

We did our final cleaning/winterizing earlier today. We closed down the vents and turned on the dehumidifier (it's placed in the bathtub on a rubber mat). The humidity showed at 82% in the rig.

In 3 hrs the humidity had dropped to 60% and there is 1" of water in the lg reservoir of the unit. I'd say it's doing okay. Is there an optimum humidity % we should strive to keep the TT at?

Any more tips/do's/don't would be greatly appreciated. We think we did it right, but if there's more for us know please sound off.

Thanks in advance!
.
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JIMNLIN
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Explorer
Our last two RV trailers were the newer aluminum framed with the sandwich sidewall construction. Condensation is a huge issue unlike our other older units with wood framed sidewalls and rolled batt insulation which were warmer and much quieter.

We lived in a 27" aluminum framed with the sandwinch sidewalls for one winter here in northern Oklahoma. Temp down in the single digits on occasion with 35-40 mph winds much of the time. Condensation was a very big issue.

I skirted the 5er with mobile home skirting which helped keep the cold out of the floors. I made 1/8" Lexan storm windows for all the many windows. That also helped keep the trailer much warmer but still had moisture issues

We tried cracking the vents but all that accomplished was a colder/drafter trailer which caused the heater to run twice as much. We were using a 30 lb propane bottle every third day when it was cold.
We set two 12" fans up but all that did was move the same air around. Who wants to live with a fan blowing air around in the winter. Still had the same condensation problem.

Finally our RV dealer service mgr who lives just down the road says to get two dehumidifiers. We tried one but found it took two to finally get rid of our condensation problems.
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RoyB
Explorer II
Explorer II
We do the opening of the roof vents a small amount which helps us...

Since we do alot of camping off the batteries we really like the O2COOL 10-inch fans from WALMART/LOWES that operate from both 120VAC using a xfmr and internal D-CELLS batteries. These move alot of air inside the trailer...

Having the fabric tent ends adds even more problems with condensation. Everything that sticks out drips water haha... The metal tent bows inside the tent bed ends are very known for dripping water on your nose haha...

ALways a good idea to have a couple these fans around...


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allen8106
Explorer
Explorer
herbhofmann wrote:
My DW and I went on our first October camping trip and first night out when it was cold enough to get condensation inside the TT.

Question: What is the best way to prevent this? Not only the windows were wet, but also along the aluminum framing. Our first TT was Stick and Tin (and old) so we never camped this late in the year.

My thinking is to keep the trailer a bit warmer at night (DW likes it COLD) and keep the vents open (got Maxairs on order). What do ya'll think?


Open the roof vents about an inch.
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Huntindog
Explorer
Explorer
If you want your TT to last, you have to address condensation somehow.

The condensation you see on the windows is also what is happening in all of the walls and ceiling etc. But the unseen condensation is also doing damage as it occurs. Delamination is a primary concern.
Venting works. But is serious cold it is not the best option. A dehumidifier is. I run the Honda all night to power our Soleus 40 pint one. It is very quiet and actually throws out some heat.
The generator also powers all of my heat tape on the plumbing and keeps the batteries up.

Huntindog
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Mike_Up
Explorer
Explorer
We camp a lot in the cold.

Never had a condensation issue.

First, laminated trailers use sandwiched walls with aluminum tubing for strength. The aluminum tubing conducts the outside cold to the inside of the wall, resulting in condensation on the wall. Wood framing doesn't do this.

If you have the furnace on and have a truss roof with insulation, you shouldn't have any type of condensation. If you have a laminated sandwiched roof, you'll likely have the same cold conduction through the aluminum tubing.

You should leave the heat on to warm the interior surfaces so that they don't condense any moist air.

If you don't have double pain windows, you will have a lot of condensation on the windows. You can leave the windows cracked and any roof vents cracked to allow enough air flow to remove humidity.

Or you could buy a small $200 dehumidifier, find a way to rig a hose to go out through a hole in the floor, and let it drain automatically through the hose. Or find a dehumidifier than uses a switch for auto shutdown and alarm, so that you can empty the tank when it's full.

We've camped also in the Pop Up in the 30s and just keep 1 window at each bunkend opened about 3" X 4" and keep the heat around 55 deg. f. with warm clothes and blankets. We keep the heat up more when awake. The pop ups go through propane fast since they're just tents with no insulation. 😉

Love cold weather camping, hate hot summer camping but it's still better than not camping at all. With kids in school, you make sacrifices. 🙂
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djsamuel
Nomad
Nomad
anaro wrote:
FL was the first time I've seen it accumulate on the ceiling like that. It was August in FL so hot and humid are the norm. I will watch it next summer and see. Humidity sucks around here. I fight mildew all summer long. unfortunately with the trailer in the storage lot I can't run a dehumidifier. I'm gonna try damp rid next summer.


We're in Clermont, FL. In September, we were at Fort Wilderness and had no condensation, but there was defintely an issue with humidity/dampness at night. During the day, the humidity was fine, but during the day, with the sun and higher temps, the A/C compressor was on longer. At night, it would cool enough to decrease the compressor "on time". This decreased the ability of the A/C to remove humidity from the air. Plus, we were in a preferred site (loop 200) with the lake nearby and the canal right behind us. We're looking at getting a nice small dehumidifier (one with a compressor).

2013 Camplite 21BHS Trailer, Ram 1500 Tow Vehicle

goducks10
Explorer
Explorer
Elec blanket at night. Elec heater during the day.

Pool
Explorer
Explorer
We use electric heater no condensation.actually too dry, kids sinus acted up overnight.

anaro
Explorer
Explorer
FL was the first time I've seen it accumulate on the ceiling like that. It was August in FL so hot and humid are the norm. I will watch it next summer and see. Humidity sucks around here. I fight mildew all summer long. unfortunately with the trailer in the storage lot I can't run a dehumidifier. I'm gonna try damp rid next summer.
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ktmrfs
Explorer
Explorer
anaro wrote:
I understand the winter condensation issue bit this past summer we spent a week camping at Disney fort wilderness in fl. We ran the AC the whole time. We got condensation on both windows and ceiling. This was with trying vents open and closed. Any suggestions as to why? I know a dehumidifier would help but this isn't always a problem just on occasional trips. Thanks.


the AC should act as a dehumidifier. But then if humidity was real high and the AC was cycling a lot, then it may not have been able to remove enough moisture. May need a dehumidifier as well.

But I will defer to others since this side of the coast is much much drier in the summer than the east coast.
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anaro
Explorer
Explorer
I understand the winter condensation issue bit this past summer we spent a week camping at Disney fort wilderness in fl. We ran the AC the whole time. We got condensation on both windows and ceiling. This was with trying vents open and closed. Any suggestions as to why? I know a dehumidifier would help but this isn't always a problem just on occasional trips. Thanks.
2014 Silverado 3500 Duramax, SRW, Crew Cab, 4WD
2014 Palomino Sabre 34REQS -
2011 Crossroads Zinger ZT26BL - sold in 2014

jamesu
Explorer
Explorer
Being from Keizer you understand Pac NW rain. Camping in the rain I used to keep the trailer buttoned up at night, because it simply was not wise to leave the roof vents open in nightly rain/downpours up here. Used to wake up each morning to dripping windows and puddled water underneath them. I would spend a minimum of 1/2 hour every morning wiping down all the interior windows and surfaces of condensation.

Several years ago I ordered and installed roof vent covers myself: best trailer investment I ever made. I leave my roof covers open 24/7 year round. Have never had condensation since. I don't even use Dri-Z-Air anymore.

In my book roof cover vents are the best thing for this climate. Leave them open all the time, even when underway. Nothing gets in accept fresh air.
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ktmrfs
Explorer
Explorer
pbohart wrote:
Reiterating what some have said.

I camp all winter in Oregon. Coast, Mt. Hood, Southern Oregon.

I bought a $150 dehumidifier from Costco and my condensation problems are over.

Plug it in and let it run all day, all night. It is a tad bit noisy, but it actually helps to heat up the TT.

I dump 5-6 pints of water out several times per trip - water that would have been causing mold and rot.

Opening vents doesn't really work when you are camping near Government camp in February! Too cold!!!

😉


x2! Except there are many times where we dump several gallons twice a day.
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