Turned an old wine cooler into a filament dryer box - sitting at 15% humidity now

I did something similar but with a stack of clip-top storage totes instead of a fridge, since I don't have the floor space for another appliance. Each tote holds three or four spools on their sides with a tub of silica gel in the middle, and I've kept a couple of cheap hygrometers in there to keep an eye on things. Mine settled in the low teens as well and stays there as long as the lids stay shut.

The part that made the biggest difference for me was printing straight from the tote. I drilled a pass-thru hole in the side near the bottom and feed the filament through to the printer, so whatever is on the bed is coming out of dry air the whole print. That sorted out my TPU, wich was hopeless before, it would bubble and sag after a day on the spool holder. One thing I learned the hard way, leave freshly recharged silica to cool right down before it goes back in with the filament. I dropped warm pouches in once and the trapped heat pushed the humidity inside the tote up for a good while, which defeated the whole point. Now I let them sit out overnight. Your wine cooler setup sounds ideal for the big spool count though, being able to read the gauge through the glass is a nice touch. I have to crack a lid to check mine.

I tried the passive desiccant route for a while and it just didn't cut it for me, mainly because of where I live. Summers here sit around 80 percent humidity and my sealed tote woud climb back up within a week no matter how much silica I threw in it. PETG was tolerable but my TPU kept giving me soft, mushy first layers that I now realise were moisture all along.

What actually fixed it was a small heated dryer that holds two spools and feeds filament through a little port while printing. It sits right on top of the printer so the filament never sees open air. Before that I was doing the oven trick, which works but I always forgot a spool in there and came back to a warm lump of fused plastic.

Now I do both: anything actively printing runs from the heated box, and the rest of the spools live in vacuum-sealed bags with a few desiccant packs. I've got a whole brick of PETG that's been sealed since spring and still prints clean. The bags cost next to nothing and stack in a drawer, which suits my crowded workbench better than another appliance would. The one thing I'd add is that desiccant colour indicators lie once they've been cycled a few times, so go by a hygrometer reading rather than trusting the beads look orange.

This is making me look at the little bar fridge in the garage differently, it just holds cans nobody drinks. Quick thing I'm stuck on though, when you bake the pouches to dry them out again, how do you know how hot to set the oven without melting the little beads or whatever is inside them? I've got a bunch of those sachets that came in a shoebox and never thougth they had a second use. Also wondering if the spools just live in there forever or if you pull them out once they've dried out.

Been lurking here a while and this thread finally got me posting. My situation is a bit diffrent, I've only got three spools total and they're mostly PLA, which I'd assumed didn't need any of this. But after reading everyone's results I opened my PLA spool bag and the filament had that faint musty smell, so maybe I've been blaming my printer for something that's my storage. My only worry with a fridge style setup is whether the cooler temperture itself matters or if it's purely the humidity doing the work. I don't want to run a compressor all day if the dry air alone is what's saving the prints.