I designed an air dryer with a Peltier module to keep my coreXY printer filaments dry while printing
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- เผยแพร่เมื่อ 6 มิ.ย. 2024
- This is a detailed presentation of the design of an air drier using a Peltier condenser.
Attached to my printers filament box it keeps my filament dry while they are mounted on the printer.
I mentioned Stefan's video @CNCKitchen related to the effects of humidity on filaments : • WHY you NEED TO DRY yo...
As well as Brett Beauregard's Arduino PID library : github.com/br3ttb/Arduino-PID...
You will also find al the files involved in the project here :
drive.google.com/file/d/14gjB...
Post publication comments :
As some of you suggested, it could be a good idea to use part of the heat produced by the Peltier module to heat up the inside of the box.
But it is necessary to continue to cool the module with fresh air otherwise the all assembly will heat up as well as the cold side which would be counterproductive.
00:00 Intro
01:16 Principes
04:15 Integration
09:38 Electronics
11:16 Software & features
11:43 Conclusion
Why is this not more commonly used it's an amazing idea
Thanks for the detailed video. There are so many TH-camrs who roughly tell you what they did, not so with you. You put so much effort into explaining everything to us, the community, in detail. I'm excited.
Thanks Thorsten
Agreed, well stated Thorston. Listening/Watching, your accent is awesome, lol. Your in depth explanations are exceptional and I really like your design choices. Great stuff.
Thanks Jack,
Happy to know you liked my accent !
This is INSANELY Awesome! Thanks you so much for making the project and showing it to everybody with great details in this video - oh, the special effects blew my mind 😱😆
Thanks for watching GeekDetour.
I'm glad you liked it and watched your video about Sunlu Filament Box.
I wonder which solution, condensation or heating, is better in terms of electricity consumption.
With the condenser, I maintain two coils at 15% humidity with a consumption of 30W and I was impressed by the 350W of the S4.
Great job, very well built!
Thank you for sharing your work. Fantastic detail and explanations.
Thanks
Thanks again for sharing looking forward to anything else you put out.
Nice to see you again.
Thanks
Thanks for sharing this! its was fun to see all the prosses and components
Enjoying learning about your interesting design ideas. Subscribed if you hopefully have more to share! Reminds me of how victorian engineers used to make their own tools and measurement devices
Thanks, I'll try to share more.
You deserve alot more subscribers your content is great
Merci for the wonderful video!
A suggestion to improve efficiency, have the hot side within the chamber with ducting to redirect the air back to the filament. As the temperature drops in the case less and less moisture can be absorbed by the air. Since the water removal occurs at the Peltier surface where the temperature is locally very very low it shouldn't cause issues and may actually help to alleviate the frosting issue. Instead of pumping some of your electrical energy out of the enclosure you could recycle it inside. This would allow you to reduce the number of sealing surfaces required and also implement a pseudo-heater.
As far as moisture removal, a wick works great but you could also have a funnel which collects water into a very small holding tank with a float switch and water pump that occasionally pumps the water out through a tube--this would provide another way to seal the case and it is very unlikely that significant water evaporation could happen through the water drain as diffusion through thin tubes is almost negligently low give that there would be no convection over the water surface.
Edit: I've just read some of the discussion about the fear of increasing the enclosure temperature to the point of burning out the Peltier Device. I suspect that you would likely see an increase in enclosure temperature however given how much of it is made of aluminum it may conduct and radiate heat out at a high enough rate to counter this. Again, having the hot air from the Peltier heat sink redirected very locally to the filament may help to ensure that the material receives the majority of the high temperature, low humidity air to remove moisture, which would then cool somewhat through conductive heat transfer via the frame and plexiglass as it circulates back towards the Peltier cold side.
If you wanted to get REALLY fancy you could have a two stage heat since with one enclosed set of fins within the enclosure and another set outside of the enclosure, then if the temperature gets too high in the enclosure an exterior fan can extract additional heat.
I don't know, but it is a very fascinating device that you have created and shared. Thank you again for inspiring such an interesting conversation!
Hello Liam, thanks for your comment.
I already discussed this point in the comments.
The idea of using the consumed power to heat the inside of the box is good.
This will increase the dew point and the efficiency of the condenser.
But I think that the idea of keeping all the power inside is not good.
The principle of the Peltier effect is to maintain a temperature difference between the two faces (inside and outside)
If you put outside into inside the all system will heat up and the temperature difference between the air and the cold surface will not change or worth decrease.
I presume that the good way to do it would be to have a bigger heatsink with an outer fan connected to a smaller one heating the inside with the inside fan.
A smart fan speed management should be able to maintain a target temp inside the box while maintaining a low temperature of the Peltier.
@@workshopfeedback I was toying with the idea of using peltier for a dry box. Never got to building it. The idea was that the box would be vented and the incoming air would pass over the peltier to remove moisture. The hot side would have 2 radiators. One of them enclosed in a duct so that the box air could be recirculated over it to heat the box. Second half would be cooled by external air as needed. Why I ditched the idea was that peltier can keep around 60degree temp difference. If I want the cold side to be -10C then I'd need to keep the hot side not over 50C. The box temperature would not be nearly enough to dry nylon etc. Maybe it would work if I would use only external air for cooling the peltier and use something else for heating. For storeage I use silica gel that I throw in the kitchen oven once in a while. Keeps the box humidity around 15-20%.
You’re awesome. I’ve had the idea to use a Peltier cooler as well a couple of years ago but I didn’t have the skills and knowledge to make it happen. Im very thankful for your video sir and I’m a bit more confident and a tad bit more knowledgeable (after all these years 😅) now so I’ll try it again utilizing a heater as well to increase the dew point within the dry box.
Thanks, I hope it will help you to success
Keep up the inspirational work!
Thanks
Votre vidéo est très complète et structuré, merci et félicitation !
Merci !
très beau boulot !
Peltier cooler is the right way to go. I think you can improve efficiency by designing a textured water condensing plate.
You can also make the collected water wick up to the heatsink to be evaporated.
During my test, any attempt to increase the condensation surface resulted in an increase of its temperature and of the minimum humidity level obtained. I finished to go to the simplest.
Very cool! Thanks for sharing! I wonder if it would be able to get the humidity even lower if the defrost cycle was more frequent, to collect the water. Every few hours, maybe
I dont think there's so much water to evacuate.
There's no dropdown of the humidity rate after a flush.
I rises a bit and returns slowly to its original state.
Thanks for your suggestion
Thank you for the wonderfully clear explanations of your projects! Would it make any sense to use the hot side of the Peltier as the heat source for the inside of the box?
Thanks Michael,
Yes ! it absolutely makes sense.
At least on a physical point of view as it would raise the dew point.
Its also mechanicaly possible to have part of the heatsink heating the inside of the box.
I presume the inside fan could also be placed on the interior heatsink.
Needs a bit more space but would be a good enhancement.
There are electrically powered osmotic membranes used for electrical cabinets but I have no idea who manufactures them. Your Peltier idea is brilliant!
Thanks
There are but the prices are ridiculous.
I love the video. Thanks you!
Thanks
Very cool. Personally I’m going to try also having the hot side in the box to let the filament temperature get up somewhat, like what you see with a honey drier. I’ll also include a heat exchanger for outside air before the cold side though. Or maybe I’ll make a cyclic desiccant dehumidifier.
Also you forgot freewheeling diodes!
Hi James,
Using part of the power to heat the inside should be nice.
You may be able to get a very low humidity rate.
Let me know what you did.
Thanks for the diodes, you're right, they are missing on the fan drivers.
Very nice, I'm interested in the power consumption of the dehumidifier, Peltier modules aren't known for their efficiency :)
36W
Why not use the hot side to heat up the chamber? To get higher temperature at remove more water from the filament? You can also reverse the current in the Peltier to faster deice, but that might be overkill.
Cold side has less power due to inefficiency but the walls will absorb heat. If heat overpowers frost, the ice will melt from the surface evaporating the water.
One way is to vent heat in at the start of the cycle only, then turn the valve the other way to vent to outside. Another servo might be overkill though
Yes, using the hot side to heat up a bit the chamber could be interesting as it would increase the dew point temperature.
Not easy for me to integrate on the existing design but should be tested.
When cutting off the power supply and the external fan, the cold face heats up quite quickly.
I'm not sure that the module would apreciate the reversed power
it would be interesting to compare the cooling vs heating methods
In my mind, heating is used to dry wet filament as the condenser is used to keep it in a dry atmosphere
One suggestion to increase gathering condensation, is to periodically flip/flop the positive and negative going to the Peltier heat pump.
As many may know, when you flip pos/neg to neg/pos, the cold side now gets hot and the hot side now gets cold.
So while it's running, you might be able to calculate how much ice build up there is on the cold surface, then flip/flop the voltage and probably PWM it to not be fully on, just enough to allow it to warm the surface enough to melt the frost buildup.
The frost will then turn into water and rain out.
This will increase dehumidification, because when frost is there, dehumidification efficiency is lowered and even just stops.
Just like a home dehumidifier when the coil freezes. On those units, the compressors have a flip valve that literally does the flip/flop thing, but not with voltage, rather, with how the coolant is moving. It "reverses" when frost is detected. The "cold" coils warm a bit to let the frost melt. Then flips back to normal operation.
Efficiency is increased with this process.
Thanks, you're right.
In fact I don't reverse the voltage but just switch the power off and let the device temp between both faces to stabilize.
It has a real effect on the efficiency. By flushing every 4 hours I obtain a humidity rate below 15%.
@@workshopfeedback Nice!!!
@@workshopfeedback I recently had this idea pop into my head aswell, and then I looked it up if others did it before me, only I had a slightly different flow in my head.
As I understand it, you are now effectively cooling your filament chamber right? If the temperature drops, the relative humidity rises, and the dew point also lowers (to sub zero).
My idea was to guide the air from inside the filament chamber past the peltier element (ideally also with a small heatsink on it) where it condensates, then the colder dryer air should flow past the hot side of the peltier to heat it back up before it re-enters the chamber. Hot air will be more capable of taking up moist from your filament, and you might raise your dewpoint above the freezing point, eliminating the frost issue.
At a chamber temperature of 40 degrees, your dew point will be at 0 degrees with a relative humidity of 8.3%. I think you should steer on having the cold side at around 0 degrees by splitting the airflow after the cold part in two channels, one directly into the chamber, and one past the heat side of the peltier. If the cold side is going sub zero, redirect more air directly back into the chamber, and if the cold side is getting to close to the dew point, cool the hot side with the cold air.
At worst you simply have a heated chamber, which is how most filament dryers work anyways, at best you have an active dehumidifier
Hi Henkheijmen,
I confirm the system slightly cools the inside of the box and I agree that it is necessary to use part of the heat produced by the Peltier to warm it up. We need a large heatsink on the Peltier and another small one that heats the inside of the box. By regulating the speed of the fans located on each side, we should be able to maintain between 30 and 40°C in the box. This would raise the dew point and provide better results.
I understand the benefit of keeping the cold side above zero to avoid ice, but experience has, for the moment, told me the opposite: the colder the Peltier, the better it works. I simply let the peltier warm up regularly to let the ice melt.
Concerning the radiator on the Peltier, I never managed to get good results, probably for the same reasons as before.
Cool project. I've seen commercial drying cabinets that have a dryer that drys desiccants to atmosphere then seal up to have the desiccant dry the cabinet. Did you look into this system?
I tought to this option recently but never seen any product like this.
If you have a link, I'd be pleased to see that.
I don't think it's letting me post a link but search. UNDERSTANDING EUREKA AUTO DRY BOX AND ITS USAGE. You've inspired me to try and make one myself. I belive it will have similar electronics to yours but it has the advantage of heating the filament compartment.
@@NotWorkingAtAll Thanks, got it.
There's an interesting DIY valve issue.
Keep me informed !
It feels like venting the air from the hot side outside the box is a bit of a waste as increasing the temprature will also help draw moisture out of the filament. why not keep both sides of the peltier ellement inside the box?
You could actually just put a commercial peltier dehumidifier inside the box so you can get both some heating as well as the dehumidification effect.
You are right we could use the hot side to heat the box but I don't think that putting it inside would be a good idea as it will probably overheat.
Using a commercial one could also be a solution but still outside of the box.
And I guess commercial dehumidifiers keep their cool surface above 0°C to prevent freezing.
This gives a dew point around 25% or 30% humidity at room temperature.
@@workshopfeedback hm yes. thinking about it some more I suspect the move might be to initially draw outside air over the cold side to condense the water and then have the now cold and dry air go over the hot side to raise the temprature, drop relative humidity further and recover some of the energy used to cool down the air, before releasing it into the box.
still feels like continually introducing fresh air into the system can't be quite optimal as you are also displacing the allready dehumidified air by doing so but you are probably right that keeping everything closed naively would lead to overheating before raching optimal dehumidification.
Then again having the inside of the box quite warm means that the relative humidity reached at a dew point just above freezing woud be quite a bit lower than at room temprature.
maybe a dehumidifier plus a thermostat to prevent overheating could be a nice and lazy solution as one could just get some off the shelf devices, drop them in a box with filament and be done with it.
I think if you keep both the hot and cold side inside the chamber it may be more thermodynamically efficient for both the chamber and the outside room
Using the hot side to heat up the chamber seems to be a good idea.
Using the heated air to refresh the peltier module is not as this will also increase the temperature of the cold side.
@@workshopfeedback My idea for a similar project was to use the hot air to actively drive moisture out of the filament, either on the spool or in the path to printer. But since I learned about molecular sieve, I've just been printing out of passive MS dry boxes.
What's the temp inside the box while running? If you open the box while cold, wouldn't humidity condense onto the spool like taking a bottle out of a fridge
The temperature inside the box is fairly the same than outside. So, no problem when opening the box.
I had roughly the same ideas than you, but I never pushed myself to do it. Your video gives me more motivation to do it. Is there a reason to decrease the temperature below 0?
The only difference with my idea was to heat up the temperature inside.
Thanks for the video
Hello Jerome,
Thank you for your answer.
I think that your idea to heat up the box is good. This should be done using the heat produced by the Peltier Module.
Concerning the temperature of the Peltier, it depends on the desired humidity level and it's different from commercial air dryers whose function is to draw water from very humid air.
For an air temperature of 20°C, the dew point is 0°C for a humidity level of 25%.
I tried to obtain the lowest possible humidity level and i get a rate of 14% with the Peltier module at -16°C while the dew point is then at -9°C.
In all my measurements, there is a difference between the theoretical dew point and the temperature on the cold side.
Let me know if you success.
Ah sorry, I missed your very good point about the dew point. I will definitely keep you updated when I will do it.
Yay for pronunciation!
Would it be ok to use a IRF540N instead of the IRLB8721PbF?
Hi Matheus,
yes, I think that it should be ok
@@workshopfeedback thank you
Very cool! Are you open to commercial collaborations of your creations?? If so, how can we contact you? Regards
Sure if it makes sense.
You will find my email address in my profile
@@workshopfeedback 🤔 there is no email/way to contact you there
If you go to this page :
www.youtube.com/@workshopfeedback/about
Click on "Display email address" and confirm you're not a robot.
You should get it.
t'aurais pas eu meilleur temps de mettre un radiateur du côté froid du module aussi ?
J'ai essayé mais j'avais de meilleurs résultats sans radiateur.
J'ai eu l'impression qu'il valait mieux avoir une petite surface très froide plutôt qu'une grande moins froide pour obtenir le taux d'humidité le plus faible.
C'est vrai que les déshumidificateurs du commerce ont un radiateur mais ils cherchent à faire de l'eau dans un grand volume d'air, pas à faire descendre le taux d'humidité très bas dans un petit volume.
Il y a un gros enjeux de résistance thermique de contact entre le module Peltier et le radiateur extérieur. Je pense qu'il y a le même pour un radiateur côté froid.
Ca fonctionne pas mal comme ça, la taux d'humidité descend jusqu'à 14%.
L'amélioration à apporter serait de renvoyer une partie de la chaleur dégagée vers l'intérieur de la boîte pour remonter le point de rosée.
@@workshopfeedback j'ai essayé et remerqué la même chose! c'est fou ça gèle vraiment^^
𝙥𝙧𝙤𝙢𝙤𝙨𝙢
ᑭᖇOᗰOᔕᗰ
croaso
LOL, this is so overengineered :D
Just hook everything up to the printer PSU - it runs when the printer runs, good enough. If frosting becomes an issue (i.e. if you print for long periods without breaks), put in a 555 to periodically turn off the peltier cooler for a few minutes to defrost. For humidity readout, glue in an off the shelf hygrometer.
Simpler but ineffective. In this case you'd better use silica gel and regenerate it regularly.
@@workshopfeedback How? All you're doing that this solution wouldn't is turning it off when the box is opened and slowing down the heatsink fan to reduce noise, neither of which impacts performance.
I was reacting to "it runs when the printer runs, good enough.".
I don't agree with it.
For the rest, yes it can certainly be simpler, more noisy also.
For me it was also a testing device as I didn't know where I was going when I started and I needed to be able to control all the parameters.
There is a fairly fine regulation of ventilation in the box which allows me to obtain a fairly low humidity level. This would be difficult to do without a little software.
And then, an Arduino nano is not the end of the world...
Just by coincidence the colour... is that of a French flag... lovely touch...Thanks for the video
Ah Ah ! subliminal propaganda ?
By the way i have been working on a similar idea...where you would dry the filament as it is being extruded.