Bathroom Fan Guidelines

You can choose a bathroom fan designed with or without a light. In fact, you will now find bathroom fans with built-in heaters known as intermittent ventilation. In this case, the fan works by capturing and removing various types of pollutants quickly. This way, the pollutants do not have the opportunity to spread to rooms outside the bathroom. Because bathrooms use different types of fans from what you would use in other rooms, they are known as mounted ventilation fans, not a bathroom fan.

When buying a new bathroom fan, you need to determine the appropriate size. A good rule of thumb is that for a bathroom up to 100 square feet, you want an exhaust fan that can provide 1cfm (cubic feet per minute) with eight air changes per hour. For adequate ventilation, the bathroom fan should be allowed to run for about 20 minutes after the shower or tub has been used. To make this easier, you can always install a timer for automatic shutoff.

For bathrooms that are medium-sized and with an eight-foot ceiling, the bathroom fan should be rated at 40cfm. If you have a large bathroom, choose a bathroom fan that rates at 150cfm. This way, the air is pulled through the entire bathroom and then exhausted at a central site. The other option if you prefer would be to install more than one fan, such as one over the stool, one over the shower, and so on. However, if you decide to install a single bathroom fan, it should be placed near the bathtub or shower.

Keep in mind that when running a bathroom fan, you want to operate it just long enough to get most of the moisture out of the room, generally about 15 to 20 minutes. If the bathroom fan is poor quality or not operating properly, the fan may not help remove the moisture. In this case, the ducts can be insulated. Finally, you need to know about the sone level (the amount of noise it makes). With this, the higher the level the more noise the bathroom fan will make, so choose wisely.