What’s the best way to ventilate my bathroom?

Adequate ventilation in the bathroom is essential. Without it, a closed bathroom accumulates moisture and quickly becomes a damp, humid environment that is hospitable to mold and mildew growth and compromises paint, drywall and other building materials. This humidity also impacts air quality, a problem that is only worsened by bathroom odors trapped inside. And when it comes to cleaning the bathroom with sometimes harsh chemicals, lack of proper ventilation can be a safety issue.

There are a number of ways to ventilate a bathroom, but some are far more effective than others. For optimal results, it can be helpful to employ a combination of ventilation methods. An open window is the most basic bathroom ventilation system, but one that is not without its drawbacks: cold, humid and breezeless weather conditions render this means of ventilation largely useless.

Heated floors in the bathroom

Installing heated floors can help promote water evaporation on tile floors in the bathroom. It’s also wise to leave adequate ventilation space above shower walls and check that drains operate properly to discourage unnecessary moisture accumulation in tubs and showers. Decreasing time in the shower can also help to reduce humidity levels, but there still must be a way of expelling excess moisture.

poor ventilation steamy bathroomThat’s where exhaust fans come in. Installing an exhaust fan in the bathroom is the best way to ensure reliable, effective ventilation. If used during each moisture- or odor-producing activity (such as showering or using strong cleaners)—and for 15 to 20 minutes afterward—an exhaust fan helps to improve bathroom air quality and prevent the damaging effects of moisture buildup.

Bathroom exhaust fans

Bathroom exhaust fans are rated by how many cubic feet per minute (CFM) of air they move. The minimum rating required by building codes is 50 CFM, but you can determine the CFM level you need by calculating your bathroom’s area; if your bathroom is 100 square feet, for example, choose a fan rated at 100 CFM. For bathrooms larger than 100 square feet, add an additional 50 CFM for every toilet, shower and tub in the room. Fan placement also affects performance. An exhaust fan should be installed as close to a source of moisture as possible.

Exhaust fans are also labeled with a sone level, or noise rating. Higher levels mean more noise; those that register at 1.5 sones or less are relatively quiet, while fans with higher ratings are louder. There are several other comfort and convenience features available as well: a humidity sensor that activates the fan when it detects excess moisture levels or a motion sensor that automatically operates the fan when the room is occupied ensures consistent use, and a timer feature makes it easy to run the fan for the recommended length of time. Exhaust fans come in a range of styles and many also include nightlight or heater functions.