Condensation issue

Is the slab lower, below grade at this wet side? If so the moisture could be coming through exterior wall.
Hot goes to cold so slightly warmer moist air from outside would condensate to cold concrete. The dehumidifier is probably the best solution for year round control no matter where the moisture comes from. They move air mostly right where they are placed so If not placing it right in the center of the area ( like mine in the basement ), a ceiling fan will help circulate, improve performance.