I have a 100% underground basement with no entrance. Only 4 small 2' x 1' windows, one in each corner. The basement has never had any water seepage. Floor is very dry. I plan to take down the 3/4" T and G paneling and redo the entire basement with mold proof materials. But right now there is a very potent musty smell, which I would like to minimize. I have all 4 windows open all the time but this does not produce much ventilation. What can you recommend to help alleviate this problem? I thought about getting a dehumidifier. What kind or results should I expect out of this?