Negative: New and Improved Eva-dry E-500 Renewable Mini Dehumidifier

[NJKris]

I have a small travel trailer, about 700 cubic feet. So I bought two the of 500 size Eva-Drys (they are each rated for up to 500 cu. ft). I bought these for dehumidification while trailer is sitting unused and in storage. The trailer is completely closed up and covered. I monitor humidity remotely with a calibrated hygrometer. Prior to using these, my 30 pint electric dehumidifier was achieving 50-55% humidity levels in the low 40 degree range in the trailer. It is not supposed to be operated when below 41 degrees. I've had these things in the trailer for about a week with the dehumidifier off and empty, and humidity has slowly been creeping up to 62%, trailer temp in high forties. Although at that temp and humidity level there is no threat of mold growing, there is a risk of corrosion of metals. I will continue to monitor and update this post if conditions change, but I think I've reached some sort of equilibrium at 62%.

EDIT: Several weeks later with trailer sealed up and covered, and remotely monitoring humidity, humidity level never fell below 60%. Seems to be 61-62% most of the time. Better than no humidity reduction in there? I don't know, as I have yet to monitor humidity in their absence.

2nd edit: 2 months and one week later, opened up trailer to put stuff in, and noted color of crystals had changed to green, indicating they are saturated. Plugged in to rejuvenate and dry out for a full 18 hours (the longest time they should be plugged in continuously) and they were still green. Called company and was told to unplug and let cool down, then plug in for another drying cycle. 12 hours into 2nd cycle, crystals finally turned amber indicating they are dry. Several days after placing them back into RV, humidity is 61%, which is the best that can be achieved using two of these large units. My next experiment will be to weigh units when saturated, and again after drying, to see how much water they actually absorb.

Edit: 3/22/19 - So for the scientific among you, I had to plug in and dry these units out twice while sealed up in RV for winter. This time, I weighed the units when 'saturated' and then after drying (which takes 2 15 hour cycles to dry out, btw). The two units had absorbed 109g of water all together, which equates to 3.68 liquid ounces. Only 7.36 Tablespoons of moisture between the two units. Wasted my money on these. Have since bought an electric compressor style dehumidifier, but that can't be run below 41 degrees F.

[TeachTexas]

We tried these and didn't like either.

[firemedicmark]

Thanks for the comments. I had been thinking about purchasing these. I will save my money.

[jeff64]

Originally Posted by firemedicmark

Thanks for the comments. I had been thinking about purchasing these. I will save my money.

I have the Eva- dry 2000. It works ,but not that much better. If you feel the need for a dehumidifier, get one of the smaller compressor styles and pass on the electronic types. 2-3 small fans to move the air around

[A32Deuce]

I use 2 of the DryzAire. After a couple months, the crystals are gone and I have to drain the left over water. Seem to be doing an acceptable job.

[AbdRahim]

I use the small electronic dehumidifier with the pan to catch the water in the summer. I empty it every few weeks. During the winter I use Two Eva Dri and DampRid. I haven't checked the hygrometer recently, but it takes a wile for the Eva Dri to saturate. Of course the efficiency also may depend on the outside humidity, since these things are not even close to air tight.

[Larry-NC]

Originally Posted by NJKris

... It is not supposed to be operated when below 41 degrees.
...
Have since bought an electric compressor style dehumidifier, but that can't be run below 41 degrees F.

Well, maybe I shouldn't do it but I leave the dehumidifiers on all winter in both trailers. The temperature can drop down into single digits (Farenheit). It hasn't seemed to hurt either dehumidifier.

I buy the dehumidifiers on Craigslist for around $30, so my exposure is not too great.

Larry

[NJKris]

Unknown if that cold could damage the traditional dehumidifier, but they certainly don't squeeze much water from the air the colder it gets, so at best, they are just wasting your electricity. At worst, they freeze up and water ends up going everywhere but the bucket. I put a smart plug in the trailer, so I can use my phone or Alexa to turn it on and off, or schedule it to only run during off peak electric hours (I have one of those power meters, since most of my electricity use is off-peak, I think it's half the usual rate).

[Larry-NC]

Originally Posted by NJKris

Unknown if that cold could damage the traditional dehumidifier, but they certainly don't squeeze much water from the air the colder it gets, so at best, they are just wasting your electricity. At worst, they freeze up and water ends up going everywhere but the bucket. I put a smart plug in the trailer, so I can use my phone or Alexa to turn it on and off, or schedule it to only run during off peak electric hours (I have one of those power meters, since most of my electricity use is off-peak, I think it's half the usual rate).

There's so little moisture in the air that I don't think the dehumidifier runs at all when it's cold.

I always put the dehumidifiers in showers and open the gray valve so water ultimately drains directly out, can't damage anything by freezing.

Larry

[A32Deuce]

As long as your P trap does not freeze!