If you have an exhaust fan, running it is the easiest way to get the air in your bathroom flowing. However, it’s worth noting that when you turn on your exhaust fan, you’re creating a negative pressure environment in your bathroom that sucks steam and air out. In order for your exhaust fan to properly work, you need to replace that air at the same rate you’re pulling it out. This is why it’s important to crack open a door or window every time you run it.
If you don’t replace the airflow into the bathroom, your exhaust will not operate as efficiently as it could. Ever noticed moisture dripping from your fan after a hot shower? This is moisture that’s been trapped inside the vent due to a lack of incoming air.