Bathroom Exhaust Fans: More Important Than You Think

Years ago I stayed in a hotel where one shower turned the bathroom into something resembling a rainforest. The mirror disappeared, every surface was wet and styling my hair became nearly impossible. Barbaric. It was also a pretty good reminder of why bathroom ventilation matters.

Moisture is the real issue

An exhaust fan certainly helps with bathroom odors, but its more important job is removing warm, humid air. Repeated condensation can damage paint and finishes, encourage mold and mildew and, over time, contribute to deterioration of wood and other building materials.

The air has to go somewhere

A bathroom fan should exhaust to the exterior—not dump moist air into an attic, soffit cavity or some other hidden part of the house. The duct route, duct material and number of bends all affect how well the system actually moves air.

Fan capacity should be selected for the room and installation rather than simply buying whatever happens to fit the hole in the ceiling. A quiet fan also has an underrated advantage: people are more likely to use it.

Run it long enough

The fan should continue running after the shower or bath so it can remove the moisture left in the room. A timer switch or humidity-sensing control makes this easy and eliminates the need to remember to come back and shut it off.

A small part of a bathroom remodel that matters

Ventilation is not the glamorous part of a bathroom project. Nobody invites the neighbors over to admire the ductwork. But it is exactly the kind of behind-the-scenes detail that helps a beautiful bathroom stay beautiful.