3 days of butterfly valve drying

A project log for Solar filament drier

How to keep filament dry while being too poor to afford electricity.

lion mclionheadlion mclionhead 05/30/2022 at 21:300 Comments

3 days of data showed the passive valve achieving humidity 5% higher than the active pump.  

Both devices kept the inside temperature above the outside temperature.  The mane problem is the passive valve doesn't replace the inside air as much as the pump.  Inside dewpoint is allowed to rise higher with the valve, but it still has limited ability to clamp the dewpoint.  Inside temperatures didn't get as high, probably because the valve isn't air tight.  A small fan blowing air down half of the valve would replace more of the air.

The results were a bit too degraded to live with so forced air started gaining favor again.  There was the idea of a non self supporting air duct made of 3" poly tubing but poly tubing in small quantities is extremely expensive.  

The alternative is taping bits of polyethylene together to make a tube.  It's not air tight & it doesn't create a seal against the blower.  The types of blowers which are silent don't generate enough static pressure to inflate the tube.  Between the lack of air pressure & the leaks, the tube has to be self supporting to move any air.

It might be good enough just to have a 2nd butterfly valve on the bottom of the lid to let cold air in.

At least it yielded a nice adapter.  3 years ago, an adapter like that would have entailed many trips to the homeless despot, bodging together random vacuum cleaner parts.