Your bathroom is a major risk area for mold and other water-related issues. The reason is because of the high humidity in the air as well as all the possibilities for leaks. Your bathroom fan is designed to take care of one of those problems. Having a functioning bathroom fan is essential for a bathroom that needs to stay dry. If your bathroom fan isn’t moving enough air to the outside you will quickly notice it with a bathroom that stays muggy for a long time after your shower. If this is the case for you, there are a few things that you can look at.
First, is the fan venting directly outside? The fan should be connected to a duct that leads directly to the outside with as few turns as possible. You shouldn’t vent it into a crawlspace or attic since this could cause moisture issues in those areas instead.
Second, you might want to clean out your fan. Excessive dust buildup in your fan could prevent airflow. If you find that it still isn’t pulling its weight, you might be due for a replacement.