I am building a cabinet that will hold 24 filament rolls. I want to hook up a dehumidifier to the cabinet. Has anyone done anything similar, and what dehumidifier did you use? How did you hook it up?
Thanks in advance!
1 Like
Something on my bucket list items to build. My earlier research showed that most dehumidifiers for cabinets usually mitigate humidity of 30% or higher. That’s honestly too high for what I’d prefer, so I kind of shelved that for now until I get more time to research a proper solution.
1 Like
I’m currently looking at this as well.
I already have something simular
https://www.amazon.com/RJOKMT-Dehumidifier-Industrial-Dehumidifying-Compatible/dp/B0FB89DL9H/
But now I’m building my own, found you post looking for a de humidifier. I am looking for something along these lines. If this helps any
https://www.bttelecomcabinet.com/product/thermoelectric-dehumidifier-device/
Its roughly 6x6
I found this one… but it is a drainage.
I think what I want is a solid state dehumidifier… I am going to take a closer look at the back of cabinet tomorrow. The de humidifier is riveted in place, the only thing to identify it is “DRY BOX” printed on the inside the shell.
Ok… it’s bugging me so I checked it out sooner.
There is a vent on the back… I have it set to 25% humidity and the temp shows 20C, but that could be the air temp…
Looking at similar cabinets, I think its self-regenerating desiccant, basically it heats up the desiccant and vents the moisture out the back. (no drainage tube)
This is what I bought.
I got it installed and it has been running for 4-5 days now. It has lowered the humidity by about 9-10% in that time, but I can’t get it to go lower than about 29%. I was hoping to get it down to 20%. I have it set to go on at +26% and off again at 20%. So far it’s never turned off.
I really would like a better one, but I can’t find one that is small enough for the cabinet I built (10 inches tall).
Thanks for any help you can give.
That sucks… the cabinet I have that came with a dehumidifier only goes down to 25%, and jumps up to 30-35% for 10 minutes or so when I open the door.
I think I’m throwing in the towel and using that one for PETG ect, and my makeshift cabinet for PLA I’m and using these for now. If I have issues then, I’ll pick up something else :
The only thing I can think of with your humidity is to check for leaks… Caulk any seams. Maybe some weather tape for windows … around the doors to seal the air a bit better.
I have caulked every seam with silicone. I have a gasket around the door, and the windows are also caulked. I have latches that hold the door tightly closed. I don’t know what else I could do to seal it.
Two weird phenomenons: 1) there has never been even a drop of water come out of the drain hose; 2) sometimes when I open the door, the humidity will go DOWN a few percentage points, say from 33% to 31%. The humidity in the room is around 40%.
So that brings a thought that I had… seemed a bit much. But… if it’s a wood cabinet, could it be retaining moisture. Maybe pulling it from the air and then bringing it inside the cabinet. I thought I was thinking to far into it, but maybe that is a factor.
1 Like
The cabinet was made with melamine coated shelves-- no exposed wood–so that shouldn’t be a problem. Thanks for the thought—I appreciate your help.
if the water is not coming out, it is staying in. It is a numbers game. Maybe the water is condensed on the wall and not in the air that is measured. lower number.
In short the water tends to equilibrium. But when you heat the air in the cabinet, it condenses on the cooler walls. Lowering the humidity, but once the condensed water evaporates the back to starting humidity.
So it is imperative to release the water somehow.
1 Like
I’m testing that desiccant/silca dehumidifier now, been about 2 weeks.
The wood cabinet I have it in is holding @ 33-30%, and I’ve yet to do anything with it. I’m going to add some weather stripping tape where the doors are, hopefully it helps a little bit more. It should be fine for PLA either way. May try another type of desiccant/dehumidifier.
I’m still frustrated with my dehumidification cabinet. I bought two of these units Amazon.com - Grow Tent Dehumidifier, Smart Temp and Humidity Controller with External Heating or Cooling Interface, Auto Dehumidification Kit for Safes/Cabinets/Electric Box/Closets, AC/DC 85-265V, Auto Shut Off and installed them in my cabinet. They are sort of ok at the best. The LED displays often say that the humidity is 10% when my independent hygrometers show 25%+. Not a drop of water has ever drained out of either unit, but it HAS lowered the humidity about 10% from the room humidity. Still–very frustrating.
Do any of you have experience with the membrane type of dehumidifier? https://micro-dehumidifier.com/product/m-3j1r-set-complete-external-mounting-set/ They are quite expensive, but may be worth it, if I can solve this once and for all.
Thanks for any help you can give me.
What is the temperature inside the enclosure vs outside?
1 Like
I’m revisiting this - I now have a couple of cabinets that hold 90+ rolls of filament… (the caulk is taking forever to off gas, but almost there)
Basically what I am thinking, Drybox manufacturers would rather you pay $600 for a $40 box with a $50 electric drybox dehumifier. I feel they don’t market electric drybox dehumifiers outside of that as it would definitely cut out those exorbant prices. But that is my thought, I could be wrong.
Anyway, I’m finding a few no maintenance options, much on like what you already are using are a crap shoot. Key take away is finding ones that state how low you can set the R/H value, and have a built in heater with them where you can set the temp as well.
I seen a video of the M-3J1R-SET where someone used them on single roll dry boxes, but I think that is more than I was wanting to spend as well.
I think this one is promising -
AC Infinity HYDRONE 5
I think searching “electric dry box dehumidifier” has the best results so far.
120W RS485 Smart Air Dryer
RS485 Air Dry Dehumidifier
Currently I’m waiting for a response from this company -
https://www.bttelecomcabinet.com/product/thermoelectric-dehumidifier-device/
Not sure if they will even entertain answering me, as I am guessing they sell in bulk.
But one thing I did notice, there is a market for single consumers looking for drybox electric dehumidifiers. The silica/desiccant boxes are nice, but a pain to continually rotate once a week, and are not as efficient energy wise from what I’ve read as well.
I’ll drop back in a week or two and let you know where I go and how it worked.
I have a 100-ish roll cabinet that uses a Rosahl M-5J1R dehumidifier membrane and a couple circulation fans to improve circulation. Who knew a bunch of solid spools crammed together in a box wouldn’t flow air well?!
I also have a few silica cartridges in there just for insurance, but they never turn color and never have to be regenerated. Cabinet temperature is pretty much a constant 30-ish degrees C, relative humidity is 10-12%, unless I have it open for awhile, but it gets back down pretty quickly.
Prior to the Rosahl membrane, I tried using a “cabinet dehumidifier” which is basically just a peltier cooler with some control electronics. I expected the operating theory would be to cool the collector plate to below the dewpoint so moisture would accumulate as “sweat” on the surface and then drip into the tray and be taken out via the drain tube.
In practice, the cabinet dehumidifier is problematic. If you install the whole thing in the cabinet, the heat it generates gets it HOT in there, which increases the humidity holding capacity of the air, not great, and I could never get it to effectively dehumidify. So I redesigned it to only have the cold section in the cabinet and the hot side outside the cabinet, that worked in that I got good accumulation on the collector - but the plate was so cold it would freeze solid and I’d have to manually cycle power a couple times per day to the unit to allow the ice to melt, then the water would be carried away. The documentation with these things suuuuucks, I could never find a combination of parameters that would either a) keep the plate “cold enough” to continually collect but not actually freeze or b) do it’s own thawing, and eventually gave up on it. In theory it’s a very promising option, and I probably could have eventually tweaked it into submission, but the allure of the Rosahl and it’s constant process, dead simple dehumidfying was just too great.
I do have a cabinet/stand I ordered that has a electric “dry box” in it.
It has a fan on the inside, and a vent on the back of the cabinet, there is no drip or drainage.
It maintains the temp and r/h level - will only go down to 25% RH, pops up 10% when I open it, and 10-15 minutes later has dropped back down.
Works great, so I can only imagine if that same unit was for sale, it would be in the $50-$80 range at 1 unit price. There in lies the fun, finding a like unit that is available at 1 unit, vs the bulk orders dry box cabinet manufacturers order them in.
Also … you have the M-5J1R? Per their own site they have the sweaty face for that unit with 20 spools. The MDL-3 seems like the better option…
But I can also see using an enclosed cabinet where it may not be much of a factor, especially with good circulation.
In the end I think what most of us want, is a low - no maintenance solution. Don’t really care what it is as long as it’s proven and the R/H level we want, can be controlled. Be it 10-20-25 % Freaking needle in a haystack. I’m guessing the options from Chip 45 could be made to work, it’s just a matter of having the hygrometer attached, and something coded to set it to turn off at a specific point. You could get real fancy and have the circulation fans and multiple sensors tied into it (or connections for them). That would be the absolute perfect solution.
I don’t know which specific page you’re looking at, but membrane performance is strictly a function of the size of the membrane - bigger is always better, but obviously this comes at a cost.
The M-5J1R is rated to maintain 20% RH for enclosures of up to 250 liters, the MDL-3 only covers half that volume.
My total internal cabinet volume is around 350 liters, but that’s total volume - the entire cabinet is filled with spools, the actual air volume being dehumidifier is probably closer to 150 liters. It works well for the application, I’ve found.
…although their various white papers leave almost enough information to reverse engineer their membrane to create my own, if I ever get around to it I’d do a much larger one.
You’re right about what we want. Turnkey, simple, and effective.
I see my error… the website I was looking at was M-3J1R. I see the M-5J1R on another.
That is quite a chunk more $ than I was looking to spend.
From what you’ve said I find it very promising, but I only want it around 20-25% for PLA storage, 10% is perfect for others. I did find a power cord with a built in humidistat, you could use that to control it as well.
Something like this..
Temperature and Humidity Controller Plug in
Definitely expect some version of that plug in to be a part of my end solution… just need to find a cheaper alternative to the solid state membrane… which I may go with the solid state anyway, because you don’t loose any cabinet space for it. I really appreciate you chiming in, otherwise I was unsure if it would be as effective. Need to debate some pros and cons… space vs $ vs how fast I can replace one if needed …ect.