I have a waterfurnace 5, 4 ton, closed loop (3100 sqft house). Having trouble getting humidity below 64. Temp/humidity outside is around 73/99%. I've had the air set between 70-72 trying to get the humidity down, but I can't crack 64%. I turned the fan to auto, which helped some, but not enough. even with outside temps hovering 80 (temp set at 72 indoors still), this thing isn't removing enough moisture. What does it take without freezing to death?? I have a tech coming Fri, I just want some knowledge when he shows up. What should he be looking at to fix this?