Answer:
We had this same problem on our sun porch. In WI, the winter temps are extreme and condensation collected on the porch windows, enough that water ran down the walls and collected in puddles on the floor. Most alarming. We found that if we cracked one window about three inches, enough of an air flow was created to stop the problem. It made all the difference.... no condensation. Of course, pick a window that is "down-wind" from the weather.
Hope this helps you.