A theory about bed condensation in hybrids

[SteveMM]

I was reading the thread about bed condensation and was puzzling over it. We've never had the problem even once. I think I now have a theory about what causes it in some campers but not others. Let me know what you think...

We bought our 2013 x17z about a year ago, and have camped in all temperatures. We took it out in December when it was barely above freezing, and had no condensation. We also took it out in June when it was 90-some degrees outside. Again ... no condensation. The only thing I've ever noticed was a *little* moisture on the inside of the bunk end, but that wasn't enough to bother me.

So, here's my theory: When we sleep in our camper, we use sleeping bags. So, the heat created by our bodies is mostly inside the bag. Maybe people who use comforters or heated blankets, which trap the heat under the blanket and up against the mattress, are the ones having these issues? One would think that in the case of those using a comforter (particularly when two people sleep in the bed) the mattress would get warmer than it would from a person or two sleeping in sleeping bags.

Thoughts?

[DocBrown]

Possibly. We use a sleeping bag but unzipped and laid out flat as a mattress pad.

We've had condensation on the inside of the canvas above our heads in our old hybrid. To the point it was dripping off and onto us. That stopped when we started opening a small flap.

We got condensation under the mattress on our current hybrid once when we first used used it in cold weather. I discovered leaving a flap open did not help, but leaving the small window above the sink does.

[johnsoax]

I think it depends on how many people you have in the camper, ventilation and temperature. With our family of 6, my wife and I sleep in the back bunk, the younger three kids sleep on the front bunk (for now at least) and the eldest sleeps on the sofa. The front bunk is always full of condensation on the tent and under the mattress as well. My wife and I have some condensation under the mattress normally.

[SteveMM]

Originally Posted by johnsoax

I think it depends on how many people you have in the camper, ventilation and temperature. With our family of 6, my wife and I sleep in the back bunk, the younger three kids sleep on the front bunk (for now at least) and the eldest sleeps on the sofa. The front bunk is always full of condensation on the tent and under the mattress as well. My wife and I have some condensation under the mattress normally.

We've never had more than four sleeping in the x17z -- my wife and I in the front, our daughter in the back, and our son on the dinette. That seems crowded enough for us. But, again, no condensation on the mattresses.

[bankr63]

We've done both ways; sleeping bags and comforter. Yet to have any condensation issues under the bunks either way. BUT DW really likes fresh air, no matter what the temp is outside, so we always have some cross-ventilation going.

[Tunce the traveler]

I use the Jayco mattress pad and sleep in a sleeping bag and no condensation under the mattress. Ceiling and side walls a little from time to time.

[sirrealone]

I always seem to get condensation on the ceiling of the more closed off bed in our 23B. Even cracking windows, the bathroom vent and the zippers doesn't seem to help. I think it's just too much moisture from breathing and body heat and not enough circulation.

[bdreinv]

I remember the tent camping days in below freezing temps.In the early morning frost would form on the inside walls of the tent!We used sleeping bags to.

[bwft57]

It just seems to me that this is to be expected. I won't get into the dew point formula (it is not simple) but in layman's terms it is an issue just like in a home, which is why we put a vapor barrier around the house, and why the Attic has ventilation.

Holmes on Homes explained this once: "When you have a hot area that meets a cold area, it causes condensation. Same thing happens when you have a cold area that meats a hot area. It can happen in the summer or the winter."

Air is the best insulator, thus the mattress pads that are woven (which honestly look like those cheap-o AC filters that are blue) is enough to provide for a vapor area between the outside (cold) and the inside (mattress hot from your body).

I have had little issues with the 16XRB, but have not been out in every type of climate.

I have not tested it, but I am thinking that a simple reflective pad, like the ones you put in the windows would do the trick. I know from experience that it eliminates the moisture on the tent area when it is on the outside.
I use that to reflect the hot sun and keep the beds from being ovens in the Texas Sun.
I started with only one end, and that end, with a jury rigged set over, strapped down tight (no air gap you would think), it eliminated the dew on the inside. The vertical walls still had dew, but the top did not....well it did where I didn't have it covered.

So I am working on a 48"x10ft cut to fit over the foldout, so it covers 99% of the top and over the sides. I will post that and link to it here later when I finish the diagram and measurements for others to make.

Also another thought, a mattress heater/electric blanket BELOW the mattress would effectively heat the mattress and the laminated wood, this warming of the wood, *should* push the moisture to the outside, not the inside, since the temp differential is now on the outside. (since the wood is now warm). Haven't tested this, but in theory, it should work.

[tcanthonyii]

If we used gizmo's in our popup we didn't have condensation problems. I would assume it's the same in our 23b but haven't had it long enough. I really think it depends on the weather, dewpoint etc. Lots of factors involved.

[Brutalis]

I know this thread is old. I have had this issue since owning my camper. decided to deal with it. what we do is place a tarp under the mattress. in the morning flip the mattress up and wip up the condensation. the tarp keeps the water off the bed end so I do not have to worry about that condensation sitting against the covered wood, figured the mattress was cheaper to replace if we had to. after 3 years the mattresses look and smell fine. just a little pain of wiping them in the morning,

[jimovernon]

I have a 2013 x17z also. I have never had a condensation problem under the mattress and have camped in all types of weather. We also use sleeping bags. The 2013 models have a mattress with vinyl on one side which I don't think the newer models have. When it is cold outside I do get condensation on the tent end canvass however.

[CAG]

Originally Posted by SteveMM

I was reading the thread about bed condensation and was puzzling over it. We've never had the problem even once. I think I now have a theory about what causes it in some campers but not others. Let me know what you think...

We bought our 2013 x17z about a year ago, and have camped in all temperatures. We took it out in December when it was barely above freezing, and had no condensation. We also took it out in June when it was 90-some degrees outside. Again ... no condensation. The only thing I've ever noticed was a *little* moisture on the inside of the bunk end, but that wasn't enough to bother me.

So, here's my theory: When we sleep in our camper, we use sleeping bags. So, the heat created by our bodies is mostly inside the bag. Maybe people who use comforters or heated blankets, which trap the heat under the blanket and up against the mattress, are the ones having these issues? One would think that in the case of those using a comforter (particularly when two people sleep in the bed) the mattress would get warmer than it would from a person or two sleeping in sleeping bags.

Thoughts?

But you breath, I hope, while sleeping that is where most of the moisture come from.

If you have a window or vent cracked somewhere that could be why you have less condensation but check your windows in the morning and see how much moisture is on the inside glass.

When I had the popup trailer and 4 of us would be elk hunting, and sleeping in bags if I forgot to crack a window the condensation would be horrible during the night.

[adamdsgn]

2018 16XRB owner here. Since we've started using PUGs on the bunk ends we do not get condensation during the summer months. Prior to PUGs we would get condensation on the interior of the fabric when blasting the A/C in Florida summers.

As far as colder outside temps are concerned, we have camped in the mountains during sub 30 temps and do get a small amount of condensation underneath our mattresses in both bunks. I'm going to look into hypervent material once we upgrade our mattresses.

[Fiori1010]

We just replaced our X17Z with a X23B, we purchased a roll of Hypervent and never had any issues with condensation.

[Jagiven]

Honestly I think condensation is really based on how you use your hybrid. I think if you take a lot of showers, boil a lot of water, breath, and do not keep a window cracked open, the moisture must go some where. The moisture is attracted to where the "vapor pressure" is the lowest. Basically that means where is the coolest temperatures, think of morning dew on the lawn, the air can only hold so much moisture, and condenses out when the air gets cold. That is why the bunk ends tend to have condensation, as it tends to be cooler. It is also why we keep the side windows on our bunk ends unzipped a few inches, so the moisture has a way to escape, to the much cooler outside.

We rarely have any condensation in our 23B. We are old backpackers, so I like to cook outside, and I am too tall to use the tiny shower, so I will use the bath house, or take an old fashion tea cup bath. Hence we have very little moisture issues in our HTT.

FYI, we use flannel sheets and an old sleeping bag for a comforter, and have a few blankets. In the early and late season we will use an electric mattress pad if we have power. If not we put a flannel blanket under our fitted sheet.

We probably only had condensation less than 5 times in our HTT. We had it a few times when we first got it, and kept it closed up, and in bad weather when we had a huge crowd in the HTT, for the evening.

[DocBrown]

Originally Posted by Jagiven

keep a window cracked open, the moisture must go some where.

I really think this is the key to minimizing condensation. We don't cook in ours, and we open the vent and turn the fan on when showering.

For those that haven't tried this, you'll need to experiment a bit. Our old hrid was a 17ft. We had a flap open on the bunk end. That didn't work in our X20E, we found keeping the small window above the sink open does the truck.