Any Experience with Mini-Dehumidifiers?

[mrlynn]

I need a small dehumidifier to put in my little Casita travel trailer, which developed a case of mold over the winter.

I'm looking at mini-dehumidifiers, running c.$40-130. Some are 'Peltier-cycle' (no compressor), however that works. I want one with a hose so it will drain continuously and I won't have to empty the bucket every day; those seem to cost a little more.

Any experience with them? Amazon has a bunch, but I never heard of the brands (not that that means much). Reviews seem to be mostly 'Worked great' or 'Worked not at all'.

/Mr Lynn

[testcase]

Wouldn't a small heater get the job done? In my safe, I have a device called a "Golden Rod". It's like an oversized fish tank heater and, just raises the interior temperature a degree or three but, sips electricity. The temperature difference is enough to keep the contents of the safe from rusting. Heck, leaving a 60~100W incandescent light bulb burning in a closed up trailer might do the trick.

My first RV was a 17' 2010 Casita Spirit Deluxe Travel Trailer. It was a GREAT way to "test the waters" re RVing without spending a fortune. In the four years I owned it, I logged 50,000+ miles. Great memories!

[Paul F.]

Forget about any of the little Peltier ones. They have a duty cycle of removing like a PINT of water from the air a day. For even a modest sized trailer, you need one that will remove more like a GALLON a day or more.

Buy a small compressor type unit. If it was me, I'd buy one that has an "auto restart" feature if the power goes off, set it for continuous duty, and put it on a timer that runs it for a couple hours in the evening, and a couple hours in the morning. I would also put a fan at the other end of the trailer, to circulate air (move the damp air towards the dehimidifier, and the dry air to the other end).

I don't have any specific brand recommendations for you (I have one of those never-heard-of-em brands, which has worked OK, but lacks the auto-restart feature that I suggest and want in my NEXT dehumidifier).

[davemchine]

I bought a well rated unit on amazon and it didn’t do anything noticeable.

[OWC Jamie]

A refrigerant dehumidifier isn't going to work much below 50 degrees and freeze up not too much more below that.
Desiccant models can suck down some electricity but I don't know how they compare to just a small heater.
Guy down the street left his Motorhome plugged in but he also tented it .

[mrlynn]

Yeah, the low temps in winter can be a problem, though dehumidifiers generate some heat; at least the condenser types do.

The Casita is pretty small (17' overall, 7' wide). I would just leave windows open and maybe a fan circulating air, but I have a Calmark cover I put on in the winter, and even without it there's no way to keep rain out of an open window (windows slide). I'd like to build a carport, but there's no room where the trailer is now.

Funny thing is, previous winter there was no mold problem. This year there was; don't know the cause. Had some warm spells in February. Also I sometimes took naps in the trailer (to escape my son's five noisy kids—family living with us while a house they bought is undergoing massive repairs). I used a small 'milk house' heater; maybe I humidified the small space, too, by breathing.

EDIT: Peltier types can also freeze up. One type that can't is a 'dessicant' dehumidifier. Amazon has a little (13 pint) one:

https://www.amazon.com/Ivation-13-Pint-S...pa?ie=UTF8&qid=1525088815&sr=8-1-spons&keywords=desiccant+dehumidifier&psc=1

but it has no reviews. Know anything about these?

/Mr Lynn

[testcase]

Those "Keep-Dri" bags WILL freeze. When they do freeze, they burst at a seam spilling a gelatinous mess which is very difficult to remove. If you choose to use this type of crystal dessicant, you'd be wise to have a large bucket under it to contain the mess should the temps dip below freezing.

[ztirffritz]

Here's a used one for you. Might be overkill for the application though:

https://www.rinkequipmentresource.com/ar...ifier.html

[mrlynn]

ztirffritz wrote:
Here's a used one for you. Might be overkill for the application though:

https://www.rinkequipmentresource.com/ar...ifier.html

A little large for my 17' trailer, I reckon.

/Mr Lynn

[mrlynn]

testcase wrote:
Those "Keep-Dri" bags WILL freeze. When they do freeze, they burst at a seam spilling a gelatinous mess which is very difficult to remove. If you choose to use this type of crystal dessicant, you'd be wise to have a large bucket under it to contain the mess should the temps dip below freezing.

The dessicant dehumidifier does not use any type of crystals. Like the industrial-strength dessicant machines (see ztirffritz's post), it uses a multi-faceted ceramic wheel with a dessicating surface. The wheel soaks up water from the atmosphere, and then passes past a heating element that removes it.

These are said to be good to 32º F, and I assume will work below that, but these home units then run the risk of the output water freezing. The larger ones I gather remove the water with a blast of hot air exhausted outdoors.

The new Ivation unit interests me, but it's so new it's not even on Ivation's website yet.

/Mr Lynn