This information might explain a little.
Caution… There is some science involved…
Hello @jimandyen ,
Thank you for that.
It seems that my curiosity in drier design is being taken incorrectly.
So that I may clarify, I worked as a technician with a company that designed/made/calibrated environmental sensors accurate to better than .02% in some cases. For a number of years.
As such, I do understand atmosphere.
What I do not understand, is why the makers of filament driers have no escape for hot moist air.
Just to witness the effect, put a filament that has been exposed to the air for some time, in the drier turn it on and leave it for 2 hours.
Then lift the lid up and put your face close to it.
You will feel warm moist air.
That warm moist air is just sitting there with no where to go.
As I have stated before, “The Sunlu driers have a fan in them”, what is the point of simply moving hot humid air around ?
Cheers.
I’m not sure why they don’t either. I kind of know what you are talking about and I noticed that the article I mentioned didn’t talk about an air vent either.
Well, that is an interesting find !
It would be very interesting if Sunlu happened upon this and bought out a “Revolutionary new filament drier with a vented fan”.
Maybe Creality drops by and sees your post, then, voila, a new “you beaut” Space drier with venting fan.
So, it looks like we are on the right track anyway 
Cheers.
Hello every …
The subject about humidity and the associated filament driers doesn’t seem to leave me alone.
It is just one of those things I know various things about, but, not everything and it is bothering me and I need answers before I go spare.
I would VERY MUCH like to chat with someone in the research/design department that were responsible for the making of Sunlu/Creality/or other brand filament driers .
Why … … because, things don’t add up !
I have some reasonably accurate sensors for temperature and humidity. (they don’t need to be as accurate in reality … a couple of % is good enough to see what is happening).
OK, first question (which I have confirmed), does the filament drier need to vent the humidity ?
If the answer is yes. how is it best to do it and why are driers not made to do so.
Next question, when you are satisfied that your filament is dry enough and you put it in a vacuum sealed bag, why put a silica gel bag in with it ?
Where is the humidity coming from when the bag is so air tight nothing can get in? (you have sucked all the air out)…
Please don’t tell me the answer is 42 .
Cheers.