The only effective way to prevent mold is to attempt to keep indoor moisture levels low. A properly vented bathroom shower fan will remove moisture and decrease the humidity in your house.
CHOOSING THE BEST
EXHAUST FAN The most important feature in a bathroom shower fan is its ability to remove moisture not only as it’s created but also while moisture
droplets are floating in the air prior to condensing on the walls and ceilings. In order for a bathroom fan to do its job you need to focus on five main points:
• Sizing the fan to the room • Placing the fan in the best location to succeed • Installing the fan properly • Mitigating fan noise • Timer switch
SIZING THE FAN Prior to purchasing your bath- room fan you’ll need to size it to your room so it can adequately handle the airflow for that space. That means you need to match the fan CFMs to the size of your bathroom. Most people size the fan to the room dimensions cor- rectly but fail to factor into their calculations the length of duct run and elbows. Determining the minimum CFM of your bathroom is easy, simply multiply the room’s width × length × height × 0.13. Many fans will list the maxi- mum duct run that is allowed. Remember to include the duct run length and any elbows in your cal- culations. Adding an elbow con- nector or an external vent hood with a backdraft preventer will add approximately 10 to 15 feet of duct length. You may need a higher CFM rated fan if your duct- work is long or complicated.
This loft ceiling will be home to the new bath fan on this project. Inspect the framing to determine the best duct path and mounting position for the fan.
Establish a wiring path for the power supply and switch control.