Drymesh or hypervent under matress

[gbaglo]

I went out to the trailer yesterday to put some stuff away. One of the front bench cushions was up against the wall and I had to move it. Was rather surprised to see moisture on the vinyl of the cushion and the wall. Wasn't much and I had been running an electric heater for several hours. On the other hand, nobody had been in the trailer breathing and I do have two Dri-Z-Air containers in use.
Can't wrap my head around the idea that ventilation is key, given the amount of rain we get here, but I think with the heater moisture had to condense somewhere and that I should have opened a vent.

[paulk]

Originally Posted by gbaglo

I went out to the trailer yesterday to put some stuff away. One of the front bench cushions was up against the wall and I had to move it. Was rather surprised to see moisture on the vinyl of the cushion and the wall. Wasn't much and I had been running an electric heater for several hours. On the other hand, nobody had been in the trailer breathing and I do have two Dri-Z-Air containers in use.
Can't wrap my head around the idea that ventilation is key, given the amount of rain we get here, but I think with the heater moisture had to condense somewhere and that I should have opened a vent.

I would bet the moisture formed before you started the electric heater several hours ago. In an environment that changes temperature, that wouldn't be surprising. Say it's close to 100% humidity outside, the temperature is colder at night, and during the day the humidity rises. You can get a situation where warm moist air touches the parts of the trailer that are colder because they haven't been warmed up yet. You could get moisture there. Another scenario is if you have higher humidity during the day and it cools at night, but your cushions trap the higher humidity air until the surrounding cools.

I seriously doubt those Dri-Z-Air crystals do anything useful for long term storage. I did a quick calculation that shows that 100% humid air at 15 degrees C holds a bit over 6oz of water in a 17b. I don't know how much those crystals weight and how much water they can trap, but only a few air exchanges are going to overwhelm their capacity I think.

I'd go for one of those small Peltier dehumidifiers and try to keep the trailer as air tight as possible during storage. One of them that I saw extracted 20oz/day in ideal conditions. If you can limit air exchanges to less than 10-20 per day, then it should reduce the relative humidity by enough. They also release waste heat, which is useful in further reducing the relative humidity.

[Fox hunt]

I use a little dehumidifier works great - I had lots of issues before in the winter both with my Escape and my live in horse trailer. Love my little dehumidifier

[PGDriver]

Originally Posted by Fox hunt

I use a little dehumidifier works great - I had lots of issues before in the winter both with my Escape and my live in horse trailer. Love my little dehumidifier

Kate do you have a picture, make or model of your dehumidifier.


Cheers
Doug

[NW Cat Owner]

I put one of those Eva-Dry devices in the trailer. The color in the window had changed from orange to dark, so I plugged it into the house to dry out and refresh. It's been almost 24 hours and the beads haven't changed color. I need to go to their site and find out how long it's supposed to take, but I thought it would be done by now. It might not help that it's humid in the house, so that could be slowing down the process.

Anyone know? Thanks

[cpaharley2008]

Have you ever felt how hot those get when recharging? Mine took a couple of days and after feeling how hot it got I decided otherwise to use them.

[Ron in BC]

Originally Posted by paulk

I think the mechanism at play here is that your body is 98 degrees Fahrenheit, and even if the bench below is heated to room temperature, that's still 30 degrees Fahrenheit cooler than your body.
when it reaches the cooler 68 degree Fahrenheit room temperature surface under the bed.

That doesn't reflect my findings when I measured temperatures when doing my Ikea slatted bed base mod.

The areas with just reflectix or exterior hatches are very cold. In my case the outside air temperature was -1*C. The temperature on the hatch and surrounding reflectix was -1*C. Air temperature in the trailer was about 20*C.

It's my belief, that unless you improve the wall and hatch insulation in that area, allowing warm moist interior air into an area with ice cold walls will only transfer the moisture problem in that area.

Ron

[Bobbito]

I think Ron is right. I had the same concern.
Bob K


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[Fox hunt]

It is n Eva dry small electric dehumidifier you have to empty the water container every week and requires electricity so might not work for trailer storage. I use it all winter when above freezing and when I camp in the winter. You can get them bath and beyond stores or Amazon about 60.00

[Fox hunt]

I don't like the ones with the chemicals etc.. mine is doest change colors or recharge or anything it just quietly pulls water out of the air and deposits it in a cup thing. But you do have to plug it in

[gocamp]

Passing along a eva dry, damp rid review if interested.
Panbo: The Marine Electronics Hub: Eva-Dry your boat interior

Then toward the bottom is a link for Practical Sailor in-depth evaluation of wired and chemical dehumidifiers.

[tdf-texas]

I guess I might be in an area that has higher than normal humidity - it's usually about 100%. So, I have had great success keeping my trailer dry with this:

https://www.amazon.com/Frigidaire-FF...248915011&th=1

I just plug it in, run the drain hose over to the bathroom floor and let it go. The bathroom drain has a Hepvo valve so no moisture comes back up from the drain and I leave the grey tank drain valve open so it doesn't fill up. Runs like that for months while stored.

If I didn't keep the moisture down, mold would have a field day.

[rbryan4]

That sounds like an excellent idea when the trailer is stored Tom. Of course, we aren't nearly as humid as Baytown, but we do have really high humidity from time to time.

[Tom W]

Under the bed we use "Mortairvent" which is cheaper than Hypervent/Drymesh.

We also use a Caframo Air Dryer to keep humidity down during storage. It uses less than 100 watts.

Both are used in boats and I got them at Steveston Marine in Vancouver. The Mortairvent probably could be gotten from a bricklaying contractor for very little. It is used to create an airspace between a brick facade and wood sheathing on a building.

[gocamp]

You think lowes and Home depot carry "Mortairvent" Tom? Just wondering what places you have seen it (in general). Thanks in advance.

[War Eagle]

Forgive me if someone has already addressed this in the 174 previous posts and I missed it, but with ETI putting a coil-spring base mattress in their 2017 models (at least in our new 21'), how important is adding breathing room under the mattress (like the Ikea slats)? It seems that air should be able to move fairly freely in and around the mattress's coil spring base to minimize moisture build-up under there. Insight or thoughts?

[tractors1]

Originally Posted by War Eagle

Forgive me if someone has already addressed this in the 174 previous posts and I missed it, but with ETI putting a coil-spring base mattress in their 2017 models (at least in our new 21'), how important is adding breathing room under the mattress (like the Ikea slats)? It seems that air should be able to move fairly freely in and around the mattress's coil spring base to minimize moisture build-up under there. Insight or thoughts?

We had ETI's supplier make a custom (firmer) mattress using coil springs for our 21 and have had zero mold/condensation issues - and we're in the Pacific Northwest. However, it sits on an inclined platform (head is 4 inches higher than the foot) so there is an additional space between the ETI plywood base and and bottom of the mattress.

[Ron in BC]

[QUOTE=War Eagle;184461
It seems that air should be able to move fairly freely in and around the mattress's coil spring base to minimize moisture build-up under there. Insight or thoughts?[/QUOTE]

I'm not sure what you mean by "base". We have a mattress with coil springs that sits on a plywood platform. The mattress is asymmetrical and the bottom is covered with a vinyl material. I don't think that there would be a reduction in moisture because of the coil springs because the bottom covering doesn't give the impression of being permeable.

Ron

[Tom W]

"You think lowes and Home depot carry "Mortairvent" Tom? Just wondering what places you have seen it".

Many building supply places carry it but only sell it in large rolls. Boat & yacht chandlers seem to sell it by the foot.

[paulk]

Originally Posted by Ron in BC

That doesn't reflect my findings when I measured temperatures when doing my Ikea slatted bed base mod.

The areas with just reflectix or exterior hatches are very cold. In my case the outside air temperature was -1*C. The temperature on the hatch and surrounding reflectix was -1*C. Air temperature in the trailer was about 20*C.

It's my belief, that unless you improve the wall and hatch insulation in that area, allowing warm moist interior air into an area with ice cold walls will only transfer the moisture problem in that area.

Ron

Coldness in the storage area is certainly a concern, which is why I left the storage area vents on my build sheet. My main point was that even if you fix the majority of the temperature issues by ventilating the storage areas below, you might, depending on conditions, still want a hypervent/drymesh layer under the bedding to transport moisture out from under the bed. Even in fully heated houses, people with foam mattresses sometimes have condensation issues below their mattress if the underside is impermeable. My understanding is this is why beds are typically raised and have either box springs or slats under them.