Here are some additional tips for using a bathroom exhaust fan effectively:
Ensure the fan is properly sized for your bathroom. A fan that's too small won't be able to move enough air to effectively remove humidity.
Make sure the fan is vented to the outside. If it's not, the humidity will just be recirculated back into the bathroom.
Keep the fan clean. Dust and dirt can build up on the fan blades and reduce its efficiency.
Turn the fan on before you start showering. This will help to prevent the buildup of humidity.
Leave the fan running for at least 20 minutes after you finish showering. This will help to ensure that all the moisture has been removed from the bathroom.
Run the fan whenever you're using the bathroom, even if you're not taking a shower. This will help to remove any excess moisture that's created.