You might want to try a MOSO Charcoal bag in your sewing room. Check it out online. The fabric bag contains charcoal, which absorbs both moisture and odors. You have to "recharge" the bag about once a month in sunlight for about an hour so it continues to be absorbent for about 2 years. Living on a island, we have alot -- ALOT -- of moisture in the air here, and there is no air conditioning or heating in homes here, so windows are left open day and night for ventilation.
The interior of closets would get this light yellow spotting -- the beginning of mildew -- starting on the ceiling of all places! I would have to use Clorox wipes to remove it, standing on a ladder and working above my head. A bathing suit, dried in the sun and then hung in the closet, would become damp overnight! No kidding. The bag absorbs all that. Have smaller ones under my sinks (another musty spot). Be sure to get a bigger bag if your room is large. Since the first of the month is "bill paying time" it's my time to bake the bags in the sun -- it doesn't need to be warm, just sunny for it to continue to work.
No, I dont' work for the company, but have found that it works for me! See
www.mosonatural.com for info....