There are a couple misconceptions about exhaust fans. One is that they are only for removing odors in the air and another is they have nothing to do with the quality of air flow.
Stale air and a home filled with pollutants could easily cause health issues in many people. Many factors create a bad air environment such as: pets, smoking, mildew, mold, dust mites, viruses and bacteria, cleaning materials and beauty spray products.
An excellent way to improve the quality of air in your home is to have a good ventilation system in place; this includes an exhaust fan for the bathroom. Exhaust fans that are connected to the duct work help the flow of air. With good air flow, there will be less moisture and condensation.
If your duct isn’t connected to exhaust fan in the bathroom(s), the possibility of mold is greater. When there is no ventilation, the moisture in the air is basically sucked into the attic or crawl space and redistributed in the bathroom. No circulation can cause mold to form.
A lot of condensation and moisture in the bathroom could be due to a damaged exhaust vent. A possibility of this problem is when an exhaust fan is disconnected from the duct work or when there is no roof cap. If there is no roof cap to release the moisture in the air, then all of the moisture is being released in the attic. In other words, exhaust fan must be connected to duct that is connected to roof cap and not hang in there.
We recommend for our entire bathroom remodeling projects a Panasonic ventilation fan, these are ENERGY STAR qualified where guidelines exist and help to meet the terms of state codes and green building standards.