Blowout! How Ventilation Builds Value

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Hidden in the ceiling, bathroom ventilation systems do what candles, air fresheners and open doors can’t: they replace steamy, smelly air with cool, clear air.

That’s just as good for the bathroom as it is for its occupants, because bathroom finishes and function can be compromised in a chronically dank environment.

“I think of the fan as the insurance policy for the bathroom. If you don’t get that moisture out of there, all that nice stuff you put in there won’t stay nice,” says Jim Shelton, national sales manager for Panasonic Home & Environment Co., which makes several sizes and styles of bathroom ventilation systems. In a closed bathroom that never quite drys out, wallpaper peels, cabinetry warps, towels mildew, mirrors corrode, and wooden frames swell. On top of all that, mold can settle into seams, grout and tiny fissures and cracks. Once it starts, it spreads.

Condensation is a quick and simple diagnostic, says Shelton. “If you don’t have a fan, or if your fan is not adequately sized, it will take forever for your bathroom mirror to clear.” Another test: after running the shower, leave the bathroom door open and turn on the fan. If the mirror is still fogged and the air moist after 20 minutes, the ventilation system is ineffective.

The best time to install a more powerful, efficient fan is, of course, when building new or when renovating. New products specially designed for today’s well-insulated houses can be swapped for faltering fans relatively easily by a qualified electrician. For example, Panasonic’s “Whisper Fit” fan is mounted from below and its exhaust system designed to fit in existing spaces. That means that it can be installed with minimal damage to the ceiling.

For the typical home bath, a fan should kick up a brisk breeze, not touch off a tornado. Calculate how many square feet your bathroom occupies and choose a fan that can clear that many cubic feet per minute (CFM). A 150 square foot bathroom needs a fan with at least 150 cfm’s. Thus scaled, a fan should completely change the air in the bathroom at least eight times an hour. If you are renovating or building new, be sure to specify a fan with enough power; standard builder-grade fans typically pull a weak 50 cfm, and make plenty of noise doing it.

The current generation of fans save energy while maintaining air quality. Some, like Panasonic’s WhisperGreen, use motion detectors to switch on when someone enters the bathroom, and then run for at least ten minutes after the resident has exited, to clear the air. Other models can modulate the temperature inside the bathroom as they draw in fresh air. And filter-equipped fans catch pollen and particulates, keeping air and surfaces dry and dust-free.