RTT Condensation under the mattress

[Lemsteraak]

Condensation is the stuff that forms on a hot day on the outside of your cold drink. Anytime there is a big temperature differential, condensation will form, even in the air, think fog.

I've never thought that aluminum would be a good base for a RTT because it makes a good heat sink. Fiberglass isn't much better so this is why fiberglass composites are used. The core adds rigidity and discourages condensation, doesn't eliminate it though. There are channels in the AutoHome tents that will channel away any water that forms under the mattress. If you are getting condensation under the mattress, it also means heat is being lost there too.

I've been using the anti-condensation mat that Mike has at AutoHome for a couple years now. It is first rate, very flexible and has a nice softness about it. It acts like a box spring. I've found it very good for winter camping, pretty much eliminates the possibility of condensation as the mattress doesn't touch the base at all. You can set it up so that there is airflow making the mattress more comfortable in the summer also. I recommend it but it is quite expensive, made in Germany, shipped to Italy, then across by container. I use it on all the bunks on my sailboat and they have plywood bases. Eliminates mildew and adds a little cushion. I think it would work well on RTT's that have plywood bases too. I think if there are enough people who what it, Mike can bring in big rolls of the stuff and then cut to size, should bring the cost down a bit.

I used to live on a boat and West Marine had a mat that you would put under the mattress to absorb condensation. Didn't really work that well, rather than collecting the condensation, you want airflow and that will eliminate the problem. The mesh that Mike does the job but is pricey.

Rich

 

[HenryJ]

I ordered this: Max Vent

 

[HenryJ]

I ordered this: Max Vent

Avoid this retailer: Welcome Aboard
Welcome Aboard! Catalog
11661 Martens River Circle #D
Fountain Valley, CA 92708

Phone Numbers:
Toll-Free (800) 295-2469
(714) 434-6331

Fax Number:
(714) 434-9722

Email:
welaboard@aol.com

My credit card was immediately charged a strange amount. When I inquired I was told it was a system error and would be corrected. After ten days no correction was made and when I inquired I was told that it would be corrected when the material shipped. Two weeks and now another charge to my card. Now I have been overcharged $5 on the order. The shipment had been designated to be shipped UPS. No tracking number or evidence the shipment has been made.

We will see how it all ends.

 

[HenryJ]

Well the response was that he does "owe me $5". I am not sure quite what that means as there has been no credit made to my card.

The good news is that I did not get skunked. The material arrived today from:
HyperVent Marine http://www.hyperventmarine.com/
1301 4th St
Marysville, WA 98270
(360) 657-5503

It looks like good quality material. I will install it tomorrow.

 

[HenryJ]

The material went in just fine. Sixteen feet was just right for the large RTT. I cut about 6" off one end. This gave me two pieces 92.5" long. I went to the fabric store and picked up some heavy duty headliner spray adhesive to glue the two pieces together side by side. There is a 4" flap on one side for just for that. Then I cut the width down to 69".

The material is cut pretty easily with a pair of heavy duty scissors, or shears.

This is as much as I ever dare add to the thickness. It folds up about as snug as I feel comfortable with. I do have a pretty heavy double sleeping bag inside. That is my "luxury item" no space or weight spared there. Big heavy comfy bag.

It is going to be a few weeks before we can get out and test it I suspect as the schedule is pretty full now. No regrets to this point.

 

[cnskate]

I think the open cell foam might be part of the problem. I've put either close cell sleeping pads or thermarests under my mattress and I haven't had any problems with condensation since.

 

[HenryJ]

Just an update. I did receive a refund for the five dollar overcharge. The retailer did make good on the deal. It was a bit of worry and took a while, but things did work out in the end.

I have no experience with what is open and what is closed cell foam. How can you tell, or could you describe them? Are you thinking that the additional insulation is what is reducing the condensation formation?

I know that bodies perspire and that moisture can condense too. I have heard of issues like that in certain mattresses for the home.

I wonder if a wool mattress might be a good choice? Those fibers allow pretty good airflow.

 

[EricGagne]

I have no experience with what is open and what is closed cell foam. How can you tell, or could you describe them? Are you thinking that the additional insulation is what is reducing the condensation formation?

You may be interested by this

Oooopsss, I originally posted the wrong link. Here's the correct one.

http://www.thefoamfactory.com/opencellfoam/opencellfoam.html
and
http://www.closedcellfoams.com/
and
http://en.wikipedia.org/wiki/Foam

 

[jbs]

We had lots of problems on our recent trip (CO, NM, AZ, UT) with condensation under the mattress of our Eezi-Awn. I tried putting a couple closed-cell foam sleeping pads underneath, but the effect was the same with or without. When it was cold (and it often was- we camped above 10,000 ft at least 10 nights in CO), there was always condensation under the mattress. Sometimes "damp" wasn't really the right word. "Soaking wet" would be a better description. Luckily it was usually sunny and dry enough that we could remove the mattress and let it dry while we cooked breakfast. Not exactly convenient though. I might try some kind of material under the mattress that allows air circulation next time.

Here's a picture that doesn't really capture it.

 

[AmericaOverland]

We had lots of problems on our recent trip (CO, NM, AZ, UT) with condensation under the mattress of our Eezi-Awn.

Whoa! You mean that the common wisdom that metal-skinned floors causes condensation and wooden floors don't cause as much is a myth? Could it be that the wood used to make the platform is too dense for cold weather? I would imagine that if it was made of lighter wood with more open cell structures (or whatever the proper wood cross-section terminology is), it would hold the heat in better. The density of the wood might be enough to mimic the effects of metal skins or even concrete (heat sink effect). Now, I don't know where exactly in Africa Eezi Awn tents were designed at, but shouldn't the designer have been aware of condensation in colder climes, unless he had no experience with such conditions and didn't think about how wood selection would affect condensation rates?

Anybody have advice on this? I'm having to think about some things here.

Stephanie

 

[007]

Wood, even dense wood is going to reduce condensation compared to metal.

Those with metal liners might consider rhino lining to help insulate the warm moist air from the cold metal.

I suspect that some of these issues are from propane heaters emitting a huge amount of moister into the air which condensates in the coldest lower parts of the tent. Minimal venting compounds the problem.

I would suggest an alternate heating method, An electric blanket under the mattress to preheat that area first and better venting. It would help to crack the doors a bit.

 

[skysix]

I found it on a Canadian Marine online store but it's 100$ for a 39" x 72" piece. It would require 4 of them to cover the 55" x 94" area of my tent.....that's a lot of money to spend without knowing if I'll be able to fold/unfold my tent without problems once it's inside.

We used to use sisal matting - sort of a loosely woven mat of 1/4" natural fiber rope - in our heated tents the army (one of the benefits of being an engineer - we built the field accomodations for everyone else so somehow always had decent quarters) ... came in rolls 4'wide by god knows how long. Also used it in civie life inside canvas wall tents with waterproof floors attached. Works just as well at preventing condensate from reaching anything touching the floor (even stockinged feet). Used even with air mattresses and closed cell foam pads (or camp cots) especially in fall with most nights below freezing and in the NW with 100% humidity most of the time.

Open cells foam will not only 'absorb' the foam (not really the right term - it is only in the foam initially as vapour and then as condensate on it's route downwards as it follows the cold gradient to wherever it can collect) but also prevent the airflow that would allow it to evaporate..

Take a look at many of the European campers and motorhomes. Most often the mattress is supported by a "slat" system that allows airflow. The Dethleffs campers even have hot air vents that come out between the mattress and the wall (there's a gap that the mattress is prevented from blocking).