I would like to get some input from someone that really knows their stuff on this. Got a building built in 1976 with attic fan only, no A/C in any of it. Over the years some have wanted to leave fan off and windows all closed. Outside is humid most of the time, from 85% to 95% and with the attic fan on, it will bring in some breeze to cool a bit. There has been some mold problems that have come about. There are two factions here, one that says if you open the windows and have the attic fan on, it will cause more mold due to the high humidity. The other says if you use the fan and open the windows, it will draw the air through and eliminate the mold problem as it grows due to the stagnant humid air that is trapped in the building and is shut up all the time. so the mold will not have a chance to grow with the air movement with the fresh air coming in even though it may be high humidity. So come on any experts out there, which is right, attic fan on or off better? By the way, the mold has been taken care of and have been having fan on and windows open even with the humidity and not even a musty smell thus far.