Quoted from Lostcause:
When it’s on and getting warm/hot, yes maybe but humidity will not be an issue then but when it’s off I cant see much air flow running in and out of a pin.
They are designed to be a chimney.
Even the slightest airflow pulls air up and out of the machine.
But if you want to test this for yourself, put the humidity reading card from your gun safe inside the machine. Lock the coin door tight. Read the humidity in 30 minutes.
Then put 50 silica packs in the game, and repeat. See? It's still at the room's humidity level.
Test again in 2 days, still at room humidity.
Every photographer, gun enthusiast, and basement chemist knows that you can often pull 4 GALLONS of water out of the air in a single day from a basement or garage in the summer.
That's why your gun safe has a Goldenrod, and your $$$$ Canon lives in a sealed Pelican with a giant silica pack that changes color after a few months.
From the Dry&Dry FAQ:
Q5. How are silica gel used best?
- Silica gel packets work in air-tight seal container. If they are open to air, they are constantly absorbing moisture in open air and become saturated right away.
amazon.com link »