Air Gap Spacer For Sunlu S2 Filament Dryer

If you own a Sunlu S2 filament dryer, then you probably know that the lack of a fan prevents the humid air from being properly circulated out of the box. One of the simplest ways to get around this is to crack open the case a bit during the drying process.

I popped a ¾ empty roll into the dryer after weeks in the open (and it's quite humid in the summer, around 45% right now); after 2 ½ hours the RH in the drier was stuck at 29%, and after placing the spacer this dropped to 21% in just a few minutes.

While there are a few designs that add an actual fan to pull the air out, this type of spacer is a much simpler system that is still quite efficient. My take on this idea is as small as possible to avoid blocking the airflow, and is curved outwards for strength, better bed adhesion, and aesthetics.