Sunlu Dehydrator update

The Sunlu Dehydrators were working great when my basement was 10% or less RH. Now that spring has come and the RH in my basement has risen to 20% the RH in the Sunlu's have risen to 20% as well, even though I raised the temp to 50C.

My converted Rosewill dehydrator worked well for dehydration. It had a fan that sucked in heated air from the bottom then pushed it past the filament and vented it out the top. I am going to drill vent holes on the bottom and the top of the Sunlu. I do not know the optimal air flow so I will start with just a few small holes.

Update Day 1:

I drilled two 1/4 holes in the bottom front near the feet and two 1/4 holes in the top rear on one of my Sunlu dehydrators. I did not touch the other. After one day the dehydrator with the 4 holes dropped from 20% RH to 10% RH, the other remained at 20%.

With a somewhat sealed container it is reasonable to assume that heating the filament yields a hot filament in a damp environment. I will see if the RH goes down further with time, I suspect it will. I will keep the other Sunlu unmodified as a control.

 

I am glad to see that a dryer without a timer is now available. The units I made were needed to get rid of the timer. This is a necessary device for all who print PETG.

My method does have some advantages. The temperature is set as the maximum temperature so that when the filament reaches the desired %RH the heater stops. This has a big energy advantage. The temp stabilizes at a much lower value. The %RH is thus regulated to the set value and resulting prints are more repeatable. I found that 20% RH gave me ideal prints.