Tartan

I would not store my machine or fabric in a moist environment. A dehumidifier should keep your fabric alright but I would not move my machines in. Can you bring a machine in and out when you want to sew?

Jordan

You may need to get a dehumidifier. My SIL lives in NY and she has one running in her basement all the time and it is unbelievable how much water she gets out. I think she has to empty the tray almost daily.

Battle Axe

Mine runs in the basement year round. I leave the door to the kitchen open so that I get some circulation. It drains into a small pump that pumps it up into one of the drain lines. I can hear it kick on and if I don't hear it then I need to go down and see what it the problem.

SallyS

I also have a humidity gauge, about 3" square, in my bedroom to monitor the humidity level and find it very helpful.

Doggramma

I got some Damp Rid containers on Amazon. They’re easy to use, just remove the lids and set them out. You throw them away when they’re used up. My sewing room is in the basement along with my husband’s enormous collection of old stinky books. It’s made a difference down there as it doesn’t stink as much as it did before. It sounds, though, like you may need something stronger.

Stitchnripper

Having lived in south Louisiana for over 40 years I would worry that unless you kept something running most of the year you will have problems. Are you going to sew out there? A friend recently got a minisplit system for her sewing room and loves it. It provides heat and air and hangs on the wall. So far she has kept it on but don’t know how her electricity bill is.