Run that dehumidifier all the time. Try to keep the moisture level at 50%. The bigger problem is light. High humidity and low light is the combination you want to avoid at all costs. I keep lights on all the time in my walkout basement which has big windows too. It still gets that damp feel in summer and if I don't keep on top of the humidity level I will get musty smell. The cost of running the dehumidifier and lights is way less than the loss of the fabric stash from mildew.
My basement is finished but it was done before the practice of moisture barriers on the cement floor and walls. Cement and cinder block always moves moisture even though I have a dry basement.
Good luck.
peace
Air flow is another helpful tool. Keep the fans running in summer.
Last edited by ube quilting; 06-14-2014 at 05:01 PM.