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I am looking for ideas. Do not want to reinvent the wheel

My new shop is too big to maintain proper humidity (affordably). It is conditioned, just not practical. I can obviously build a cabinet. I was thinking about enclosing a shelving unit. Maybe 4 ft wide, 8 feet tall, 18" deep as a starter. Can this be controlled with silica desiccant and a fan to move the air around?

I want to be able to store tops, backs, sides, etc as I build. My wife def wants the stuff out of the house (smile)

How much desiccant? --Mike

Probably be better off with a small dehumidifier than desiccant…

In my last shop, I created an RH area with 1x1’s butting the ceiling like go bars. I then added thick clear poly painter drop cloth stapled to the 1x1’s, then put on a pair of stick on zippers where you stick it on the poly, open the zippers, then cut the poly with a knife. I added a piece of wood to the bottom of the piece between zippers to make a simple and effective roll up door. 2 hours maybe and 20$…then just had both a humidifier and dehumidifier in there and let themselves keep each other in check.

Mine is around 2x2x4', and the heat from a 75W light bulb + 20W dehumidifier gets it to around 100-105F. The dehumidifier only collects a few drops of water in the first few hours after I close it up, and after that it's just serving as a heat source.

I haven't done much guitar building in the years since I built it, but IIRC the humidity level in summer was not as low as I'd like for bracing so I just waited for winter like usual. It does work well for drying 3D printer filament and speeding up epoxy cure.

I'll be interested to see any other replies about desiccant. Perhaps that could get me the additional drop I need. I've seen some youtube videos about using it for filament drying, and they often use a very large amount compared to the typical little packets. It needs recharged periodically by heating in an oven to drive off the collected moisture, and will probably take some time to get a feel for how often to do it.

I like your idea of an enclosed shelving unit. Ideally the shelves should be non-solid or at least have a gap around the edge so air can circulate through the whole interior, and each level should have its own doors so you don't let all the dry air out every time you open it.

EDIT: Checking youtube videos, here are two interesting options:
Color-changing silica, which eliminates the guesswork over when to recharge it: https://www.amazon.com/dp/B0F6L7PS6X
Activated alumina, which doesn't degrade over time like silica https://www.amazon.com/gp/product/B0B81VM24F

I have a set of lower kitchen cabinets with holes drilled in the shelf. I use a humidistat (maybe wrong name) that turns a light bulb and a small fan on when the humidity climbs and shuts off when it drops. I only brace tops or do other humidity sensitive operations on days that are clear and relatively dry. I’ve never had a crack or odd movement in 32 guitars over 25 years.

Never heard of the stick on zippers! Great idea! Think I'm going to try the desiccant approach (indicator beads). Put in a box, top off with a bathroom vent fan. Run a vent pipe up back and just blow dry air around. Its cheap, easy to try, and doesn't create yet another distracting project. Ordered another shelf set to do this. Stick a hygrometer in there and see if it works. Ty!