Dehumidify in storage

There is nothing special about them, they are nothing more than colorized "silica gel beads" in a container with a window..

Per HERE

"Design Technology:

Engineered with non-toxic crystallized silica gel technology, the Eva-Dry small dehumidifier will quickly and efficiently absorb up to 4 to 6 oz of moisture from the air, without any leaks or spills."

Silica gel works very slowly (Eva claims "quickly" which is not exactly true since they claim the 4-6 oz is over 20-30 days) to absorb moisture from the air, once they saturate, you have to place them in a very warm place to drive out the moisture or replace the beads.

Generally Silica gel beads can be placed in a oven at a low temp for several hrs to dry them out, with Eva it has a built in heater that you will have to plug it in to "renew" the beads when they reach saturation..

Those little units can only handle 4 oz- 6 oz of moisture each, that is the equivalent to a CUP to less than ONE PINT of water which is absolutely NOTHING in respect to how much a real dehumidifier can pull out of the air in a 24 hr period (typical compressor dehumidifiers are rated in pints per 24hr and small ones can pull 20 pints per 24hr up to 70 pints per 24hr period).

Just leave the windows open a slight crack, not enough to allow rain in but just enough to allow air movement. You can also do the same with the roof vents.. Cheaper and effective.

Get eva dry 1200 run it off 12 volt 10-12 hours a day use solar to keep your batteries topped off. Run water line into gray water tank and leave drain valve cracked to bleed off.

If I was storing Florida or Southeast outside or any high humidity area in winter a small heater and dehumidifier. Some can be adjusted to shut or at 35% or 50% humidity and so on. You don't want to simply plug one in and forget it. They have been known to catch fire. Pit it on a metal insulated fireplace/stove (what ever it is called) base. If you run the drain hose to sink make sure there is RV antifreeze in the holding tank. The small heater ill keep things inside from freezing up. Brother has a Trailer parked outside with a small heater and it keeps it in nice shape but metal, cold on the outside warm on the snide sweats and mold etc follows. I very seriously doubt those desiccants can take as much moisture as will be generated. The MH of course has dash air vents to the outside. Towables still have holes for plumbing etc so use an electric dehumidifier.

Where are you storing it?

If you are worried after spending some time in a cold climate using the RV, odds are you don't have to do anything. The humidity is because you are inside breathing and cooking. Then you get condensation due to the temperature difference.

If it's in storage, you aren't adding moisture to the air and temperature differentials are relatively low.

On the other hand in the Florida in the summer...taking action is well worth the hassle.

Thanks for the responses. I am leaning toward the solar thing with a low power dehumidifier.

We're in CT right now, but I'll also need to store in FL when we move down there, so anything I get now will need to be relevant in FL.

Also, this info is for an enclosed 24' trailer I'll be getting to move my house as well as the 36' travel trailer I have.

Florida and south Louisiana summers are about the same. My family and friends and I have stored trailers all summer long for the last 50 years that I can remember. Mold hasn’t been a problem so far.
It’s really not a problem.