The reasons for proper ventilation in bathrooms are many. Some houses do not have a bathroom fan and/or windows. For houses with operating windows in bathrooms, they may not be opened especially in the cooler months. For others with a bath fan, the unit is either noisy or undersized. Mold in the attic is also a concern without proper ventilation. There are numerous situations of mold in attics, mold on bathroom ceilings, walls, and windows. To ameliorate these mold issues, a bathroom fan could solve these problems. more... See more text