Build the ultimate dry box! Use a mini-fridge for dehumidifying air.
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- เผยแพร่เมื่อ 10 ก.ย. 2019
- You can build the ultimate dry box for storage of 3D printer filament or cameras using a mini-refrigerator to create ultra-dry air that you blow into your storage box..
You can download the fittings design here: www.thingiverse.com/thing:392...
Tell folks to be careful when boring holes in the side, on some units there are HP refrigerant lines running down the sides .Found out the hard way,.
Good thing to know! Thanks for sharing
Is there any in the top to be worried about?
Ingenious solution and brovo, keep up the good work.
If you place the desiccant in a bag rather than bucket the humidity level can go as low as 10% @32C. My outside RH is at 70% @32C. A bit of isolation around the door helps a lot. Also, people please do not us blue desiccant it contains cobalt, that is NOT good for you. Use orange desiccant.
Cool tut... thanks. Regarding cameras... below 35% humidity is not wise for lenses and cameras because the seals and lubricants fail... I hope that's is useful as a tip.
Absolutely fantastic Phil!!
I've been following the exact same path, got a peltier to get down around 17-18% RH, by letting its exhaust heat also warm up the chamber, but I'm still not satisfied.
I'm looking at a compressor based ice maker to modify in much the same way! Love your simple and clean solution, and I'm wildly excited to see something similar working so well!
In an enclosed space the whole peltier system will heat up the air (the system cannot be 100% efficient) so in long term the air will heat up to a point where the cold side of the peltier won't cool down as much. If we keep the hot side outside of the chamber, the chamber may drop temperature too much - lowering the dew point and making the condensation ineffective. I reckon there is a "sweet point" where the peltier works the best and the dew point is at maximum. It may require some sort of automatism which re-cycles the heat from the peltier to warm up the chamber but not all the time. How did you get 17%? It may be enough for me. Thank you!
Brilliant sir hope to see some new content soon
Thank you
I see you stopped uploading but perhaps you still get notifications for comments.
I'm wondering how well an old mini fridge would work for dehumidifying a large room from 70-80% RH down to let's say 50-60% or lower. I'm thinking simply leaving the door slightly open, blowing in some air, timer turning it off sometime during the day when electricity costs more and collection the condensed water when the ice melts.
@Phil G are you still making videos? You've done some great stuff, thanks.
I have been super busy, I moved my shop to a new location and have been setting a bunch of things up. But I have some ideas for some new things to test.
Hi Phil, I love this setup and I think I may build one of my own. I see that the filament storage stays at 69 degrees. Do you have another heater for that area? I would think that the constant cold air flow from the freezer would bring that down into the 50's at least. Thanks, keep up the good work.
It is just in my lab where the air is around 69. The total cooling capacity of the mini-fridge is fairly. low, the air gets reheated as it flows into the cabinet.
@@PhilGandFriends Thanks for the reply, I would not have guessed that it stays that warm. I have not had great results with just using desiccant so I think I'm going to try to make this, I love a good project!
I was indeed wondering the same, I suspected the non-insulated hoses were enough to dissipate the cold. Thanks!
would u say that can work as sort of an actual dehumidifier for bigger rooms? u know with fans pulling air from the fridge etc
great idea btw
I don't think it would be practical. You would need a higher capacity cooling unit for a whole room.
very cool! btw, where is the out connection go from the refrigerator?
If you mean the the air exiting the refrigerator, it is piped back into the box that I am dehumidifying. The air goes in a circle from the box, to the refrigerator and back to the box.
@@PhilGandFriendsOh, it wasn’t clear to me by the video that the fridge wasn’t where you were keeping the filament.. That makes a lot more sense now
Excellent presentation, exemplary results! I'm thinking of using a countertop ice maker for my icebox. It will likely require a mod to the water filling function since that won't be needed. I like the compact size but also I haven't seen any mini-friges at the low price point of yours. Any thoughts?
As long as you can get air below freezing temp, it should work. Good Luck!
This is exactly (EXACTLY) what I was looking for. I would like to make a question: would it be possible to use such system without opening the storage case?
I want to make a similar low humidity cold environment to store a high end PC. Processors and GPU's tend to become very hot after usage at 100%. Inside such environment, especially a dry one, I believe my hardware will last longer.
Regards from hot rainy Brazil.
Sure. There is no need to open the case except when you need to get something in or out.
Can you make another video showing which hose connects to the freezer and which goes on the refrigerator side and which is on top of the cabinet and which is on the side and why?
It is really pretty simple. I would direct the air FROM the drybox into the center of the freezer part of the refrigerator (in the one I made that is right in the top). (The maximizes the chance that it will flow past the cold metal part of the freezer and release the water as frost on the metal). The return back to the drybox is not critical. As far as the dry box goes, I don't think it is critical, but I think it is slightly better to have the cold air from the frig be introduced near the bottom of the box and suck the air out of the drybox near the top. (reason is: Hot air rises, so the rising air will pick up humidity as it rises). Most of all, remember that if ice-frost is not building up in the freezer, you will not be dehumidifying. The air flow should be slow enough to make sure that frost builds up.
I drilled the top hole with no issues, but punctured a compressor tube when drilling the right side hole. 😢 got to get another fridge 🤦🏼♂️
So sorry!
@@PhilGandFriends , it was a free refrigerator, Lol. Got me a new one and it’s all hooked up, already down to 35% from 60 in just a few hours.
Hi Phil and Friends. This is really great. Few stupid questions if I may: 1. Do you still use the peltier element in addition to the fridge? 2. Where in the filament cabinet do you put the inlet and outlet hoses( next to each other at the same end, or maybe the inlet at one and and the outlet at the other end)? Thanks and keep up the great videos!
I don't use the peltier element any more. (not needed). I put the inlet hose (air from the frig) near the bottom of the box and the outlet (going to the frig) at the top.
Phil G and Friends
Hi all. I made a copy of your setup. Even with a low fan speed, the RH is 35% but my temperature is 40F. 40F sounds right because it’s got the cold air from the fridge circulating. Why is your temperature showing 60F? That’s quite warm for inside the filament box? Any help is appreciated.
@@NigelPeart1 The first question is: Are forming ice in the refrigerator? If not, you will not get the humidity less than ~25%
The temperature in the storage chamber is really not important. If you are not forming ice, then you probably have fan speeds too high still.
Hello how much is the best air flow in m3/h ? If i have freezing fridge hehe and big fan for in and out like 400m3/h flow.? Maybe you now if how much degrees celsius - need for best results? And how many liters of water can absorb in one day? Maybe its there some calculation ? Thanks for answer and good video 😀
Good questions. I don't think there is a general answer that works for all configurations. A higher capacity refrigerator/freezer can handle large airflow and still achieve freezing temperatures in the freezer. But to reiterate, the most important thing for this design to work is to have ice build up on the freezer compartment. If no ice builds up, you will not get the humidity below 20%. It does not take much air flow to keep a reasonably small box dry.
hey, has this been reliable?
Would it work even better with a Freezer instead of a refrigerator?
It has been more than a year and it is still running great. Regarding using a freezer, I would say: First, a mini frig is very cheap and small. Secondly, it works fine. It does not take muck freezing capacity to dehumidify a relatively small box.
and then, u get the auto defrost/non frost cycle, that can get the ice out of the fridge. so u dont have to do that work.
At what temperature does the fridge stays at all time ? Do you put filament in the fridge too or you put beer ? :) thanks
The fridge main compartment stays around normal refrigerator temps (35-40 F). However, the freezer section at the top is around 25 F. I have not thought of putting beer in there!
The filament section in my case stays at 19celcius and humidity at 18percent.. the freezer is bigger then yours and fans too . What am I doing wrong ? Thanks alot
@@kennybeaudoin The question is: Are you making frost in the freezer? You have to see frost buildup to be getting the humidity down low. Most people have the fan running too fast, which keeps the freezer too warm and frost is not building up.
Are the STL files for the fittings available?
Yes, Here they are.. www.thingiverse.com/thing:3928329
Awesome idea. Can you share the STL files for the hose fittings? I’m going to build one. Thanks for taking the time to make the video.
Here you go. I uploaded them to Thingiverse. Let me know if you have any issues. www.thingiverse.com/thing:3928329
@@PhilGandFriends I built one but cannot get 4%. I get 20% which I am ok with but was wondering if I am missing something. It is a bigger enclosure so maybe that is it. Here is my link to the build
th-cam.com/video/Co3TR1EarLM/w-d-xo.html
I am still happy...so thanks for the idea. Ended up designing my own hose fittings
@@rrrrriggs Looks nice! Does ice build up in the refrigerator? If not, the humidity won't get below mid 20%. If ice does not build up, you should lower the speed of the fans. I also noted that your inlet into the refrigerator is from the front. (mine is from the top). You might extend it a bit to make sure the moist inlet air get's directed right into the freezer cabinet. Let me know if that helps!
Do you have stl for the thermal electric box you made before the fridge. Thanks 😊
Aren't you (by cooling the spool), turning it into a moisture magnet? Sure the air is now dry.
Understanding the dew point is important. Water condenses out of air when it is at or below the dew point. When we run the air through the freezer, we remove enough moisture, so that the dew point is lowered to below freezing. When the air returns to the dry box, it warms up (and the relative humidity drops to 5%) In order to condense out any more moisture (such as on a cold surface), you would need to cool it lower than it is in the freezer. So, cool filament will not condense any moisture out of the air.
I cant quite work this one out. as far as I can tell you are just blowing the "fridge air" into your dry cabinet. Fridge usually operate at around 45-65 RH and somehow you are drying air to
(As explained in the video), in order to get the humidity less than 25%, it needs to be cooled lower than freezing. So the air is blown through the freezer where the water in the air precipitates out as frost on the cooling coils. That is how the humidity gets to 6%.
(As I say in other comments, if you are not making frost in your fridge you will not get the humidity below 25%)
ever wonder why they don't use Peltier chips in food dehydrators ? you're jumping through hoops trying to solve a simple problem, seriously no need to reinvent the wheel
Just put a 60watt light bulb in the cabinet, drill some small holes in the top and bottom to exhaust the humid air while providing fresh air, there you go problem solved. what you have basically done is built a dehydrator
I mean seriously haven't any of you seen an easy bake oven LOL
I have a dehydrator. But: 1: The humidity will not get as low. 2: It will use a lot more energy. But I do use the dehydrator to dry out wet filament at a higher temperature. (If you want to dry out filament that is already wet you have to heat it up to slightly below the glass transition temp. A food dehydrator is good for that.). But it is not good for keeping filament dry. And it is not good for a large storage box with many rolls of filament in it.
Dehydrators remove moisture from materials. This shouldn't be confused with dehumidifying air.
Heat is used for dehydration because the material molecules require agitation to free the trapped H2O. Then the air is simply vented out - taking the moisture with it.
Air has different properties, thus different method is required. Enter, dew point and refrigeration.
Yay for physics.