I have the Creality dry box 2.0,
i noticed that there are no vents at all anywhere in the unit.
so how does the moisture escape?
should i run it with the port plug open?
I don’t think any of my dryers have vents. I might raise the lid every so often but generally just leave it be. Quite interested in the upcoming Sunlu drier, it has an annealing temperature of 110°C.
Hello folk,
I was wondering about how the humidity can escape.
I don’t believe it actually does to any great extent.
In my driers (Sunlu) I have mounted a Temperature and Humidity sensor inside half way up the back above the hinge point.
I can monitor the temp + humidity in real time and found that if I prop the front up a few milameters, the humidity drops around 10% over about 30 minutes.
If it is sealed, the humidity has no where to go. … Just my thoughts.
Cheers.
Yeah there should be some kind of outlet fan built in like on my food dehydrator converted to a filament dryer…
Hello jimandyen,
Actually, would you believe the 2 Sunlu driers have a fan; you can hear it going, but there are no vents … doesn’t make a lot of sense to me.
Cheers.
I added a 4010 fan near to the hinge and drilled some vent holes above it for better circulation and should vent off the condensation. Otherwise lift the lid 10mm-1/2" every so often to vent.
I think the ability of the air to absorb moisture is a function of it’s temperature - the dryer doesn’t so much remove the water as heat the air so it absorbs it. Opening the lid to vent the air will bring in more cold moist air which then needs to be heated to dry it out. Although there is a limit to how much moisture the air can absorb, so if the filament is very damp changing the air may allow a lower final humidity to be reached?
Interestingly it seems leaving a gap for air to get out from under the cover does help. Humidity bottomed out at about 40% with the lid closed (reel had been in a cold workshop for a coupe of months, With a 10mm gap at the top it dropped to 15% quite quickly. So replacing the air does help to dry out the enclosure.
Just to add to the whole thing. The port plug hole doesn’t seem to add or take from what I notice.
As I don’t feed from the dryer, the hole is not used or closed. Lifting the lid a few mil seems good enough to make a difference.
I do think that with this “Sunlu” and likely the Creality one, they are not thought through in their design.
For instance; my Sunlu driers have a fan in them, but, there is no “in or out” venting of any kind, so what good is the fan doing ?
As jimandyen said …
Is there anyone out there with proper knowledge on the subject to put my mind at ease ?
These little things can build up in you, you know; I’m not bald by choice.
Hello every…
Just thought I would share something I have done to 1 of my Sunlu driers.
I figured, “hot air rises” and with it should also go the humidity.
So, I used a soldering iron with a tip I use for plastic work and made 2x 6mm holes in the top.
1 about middle and 1 at 30mm in from the back.
As I have noted before I have put temperature/humidity sensors inside toward the back that lead to a display in real time.
The holes have definitely made a difference for the best.
I am at a loss as to why they are made with a heater below the filament spool along with a fan but no way for the hot air/humidity to escape.
Will now do the same for the other drier.
Cheers.
My thinking is that the process works by raising the air temp so it can absorb more moisture. This lowers the humidity of the air in the chamber, which creates a gradient from the plastic drawing moisture out. At some point the air saturation will increase to match the filament (and cardboard reel) and moisture transfer will stop - the wetter the filament the higher the equalisation point will be since there is a fixed volume of air. Replacing the air with fresh from outside restarts the process removing further moisture and equalising at a lower humidity level. For the air to dry the plastic it must be able to warm up, so the ventilation must be low enough not to limit the warming. Opening the box every hour, or making small holes to let a very slow flow would both achieve the same aim. If the humidity holds with the lid fully sealed then the filament has dried out, if it creeps back up then it’s still drying.
A bit like emptying a bucket with a sponge - each sponge will only hold so much water, once it’s full you have to change it, or wring it out. Same as the air in the box will only hold so much moisture, after which it needs to be changed.
I don’t understand that though process either.
I think putting in those breather holes will help.
I’ve seen the small humidity sensors online but not sure which ones are kind of accurate… Any suggestions…?
My S1 driers I have added 3 off 6mm holes on the top near the rear edge, that seems to work. One of them I have added a 5150 fan for circulation, unsure if it works better than the other, perhaps the holes were enough.
So these computer fans i have laying around would work.? (5 volt)
Do you use a separate power supply or tie into the dryer…?
I have the Creality dryers but I need to check their power supply rating…
I have a splitter that I plug the 9V feed into, so the 12V fan is being underdriven. I could have wired it into the board, but I couldn’t be bothered to take it apart and play with the wiring.
Got it. Thanks…
Hello jimandyen,
I am afraid I could not say which would be better really as I built my own using electronics I put together using a couple of sensor modules I ordered.
I would guess that average humidity sensors you can find online would be accurate to maybe 5% or so. Expensive ones I would guess to be about 1 to 2% accurate.
I don’t think it would matter all that much though really because lets say you put the filament in the drier and it reads 56% humidity, you leave it for 2 hours and it reads 45% humidity, ok it has dropped at least 10% humidity; you leave it another 2 hours and it reads 44%, you can see that generally you have the filament about as low as your drier is going to get it.
Weather it is all that accurate does not really matter, I just am able to choose the quality of the sensors I use when I make the units (I have been making weather sensors for some years and have a few good instruments to calibrate from).
It would be important to be accurate if you were working with bacteria though 
Cheers.
This, buy the way, was written as a question as to why the filament driers were built the way they were, with the hope someone would have insight to their design idea as it doesn’t make sense.
Cheers.