These days, homeowners are asking their builders and remodelers for bathroom ventilation that's powerful enough to ward off mold and mildew.

"In Houston, the main goal is to remove steam because of the mold issue and anything that's quiet is a bonus," says Craig Dudley of Emerald Homes, whose firm builds houses between $200,000 and $400,000.

Reducing mold, mildew, and other pollutants in the bathroom is a top priority, but it won't happen unless the fan is quiet. Sarasota, Fla.-based Richard Megee, a kitchen and bath remodeler, says one client's bathroom fan was so noisy, the wineglass rack on the adjoining kitchen wall would shake.

Tips From the Pros

Make sure all ductwork is tightly sealed. Place ventilation grilles outside of steam showers rather than directly above them. If your client's budget allows, put remote-ducted ventilation on light switches or timers. Allow 1/2 inch of space under doors for maximum airflow between the bathroom and the rest of the house.

"One of the No. 1 complaints we hear is that people hate their noisy bathroom fans. Because they don't like the noise, these fans go unused and moisture, steam, and odors are not exhausted out of the house," says Kathie Perry, director of marketing for Fantech, a ventilation manufacturer. "This can lead to mold and mildew."

So, manufacturers continue to reduce their products' sone (sound measurement) levels while beefing up their power (cfm) levels. However, much of the noise issue can be dealt with during the installation process, according to manufacturers.

Sounds of Silence

In most production homes, standard ceiling fans are flush-mounted. But in high-end new homes and some upscale remodeling projects, pros place fans in the attic and duct them outside through roof vents.

"We install fans so that you only hear air through the grill in the bathroom and not the motor," says Mike Hazen, president of Aloha Air Conditioning in the Maui, Hawaii area. But, he says, because operation is so quiet, the fan must be on a switch so the user shuts it off.

An air conditioning and ventilation contractor, Hazen notes that owners of multimillion-dollar homes have no qualms about paying extra for remote installations that typically feature higher-end ventilation products. But clients building less expensive homes stick with traditional moderately priced ceiling-mounted fan/light combination units. Although they produce more noise, these products are available in numerous finishes, including polished brass and nickel, so they complement the latest faucet looks, Hazen and other pros say.

Bathroom ventilation products range in price from under $20 for a frugal 50-cfm unit to more than $150 uninstalled for a powerful multi-function product with features like humidity sensors.

Ventilation Math

The Home Ventilation Institute offers the following guidelines for calculating the proper bathroom ventilation:

Exhaust fans should provide 1 cfm per square foot of space for bathrooms up to 100 square feet in area (based on 8-foot ceilings). For bathrooms more than 100 square feet, ventilation is based on the number and type of fixtures present (toilets, showers, baths, and whirlpools). Each fixture requires 50 cfm of power except whirlpools, which require 100 cfm. Enclosed toilets must have operable windows or separate fans.

Although they're more expensive, high-powered fans really make a difference, according to pros and manufacturers. "When you put these in you can take a really hot shower and not have any fog on the mirror," claims Megee, who often installs 106-cfm units.

In the past, one fan in the center of the bathroom ceiling was all it took to alleviate steam and odors. But these days, bathrooms are expanding to include separate toilet areas and luxury steam showers with multiple heads, so that format simply doesn't cut it anymore.

The key is to analyze the size of your space and the products in each bathroom, says Patrick Nielsen, product manager for bath ventilation for manufacturer Broan (see "Ventilation Math").

Future Features

Although ventilation units with humidity sensors are by no means mainstream, experts predict that they, along with others with timers and motion sensors that turn fans and lights on and off, will become more common in upscale homes because of their ease of use.

And Hazen even thinks bathroom ventilation can be integrated into wired houses. "In luxury homes it could be controlled by computer touchpads or other smart systems," he says.

NuTone. The Ultra-QuieTTest ceiling fan/light can be used for continuous ventilation applications. Model LS100L features hanger-bar mounting and provides powerful ventilation at very low noise levels, says the maker. It can be installed in bathrooms, powder rooms, dens, or offices. Many other ventilation products are available from the firm. 888-336-3948. www.broan.com.

FanAm. UQS series ventilators come in four sizes and feature built-in backdraft dampers, permanently sealed and lubricated ball bearings, automatic reset thermal overload protection for motors, galvanized steel housing, and polypropylene forward-curved scroll designs. The motors are rated for continuous operation and are Class-B insulated. 800-838-4074. www.fanam.com.

Fantech. Featuring a dimmable low-voltage halogen light, the VLC-64 unit is UL-listed for wet locations, allowing it to be used in shower, steam shower, and hot tub applications. It can be installed with the firm's exhaust fan to light and vent different areas of a single bathroom or back-to-back baths. It can be purchased alone or in complete kits. 800-747-1762. www.fantech.net.

Air King. The model AK150LS fan comes standard with an optional installed ceiling flange to ensure proper building rates are maintained and that no air leaks occur between the fan housing and ceiling cutout. The 150-cfm, 1.5-sone fan is Energy-Star rated and is UL-listed for installation over a tub/shower unit on a GFCI circuit. 877-304-3785. www.airkinglimited.com.

Panasonic. WhisperLite series ventilating fan/light combination units are available in three models with sleek grille designs. They feature 13-watt compact fluorescent lamps and nightlights, are Energy-Star qualified, and have sound levels ranging from 0.3 to 1.2 sones. The units can move up to 110 cubic feet of air per minute, depending on fan and duct size and static pressure, says the maker. 866-292-7292. www.panasonic.com/building.

Broan. Available with a choice of clear beveled glass panels or a frosted melon glass globe, the 70- cfm, 3.5-sone fan/light combination unit uses two incandescent 60-watt maximum bulbs. The product comes in satin nickel, polished brass, or gloss white base finishes. Many other bathroom exhaust fans are available from the firm. 800-558-1711. www.broan.com.

NuVent. DHVL series heat/vent/light units feature the Directional Heat Discharge system to focus heat on specific areas of the bathroom, the maker says. The 5.5-sone units come pre-wired with 1400W fan-forced heating elements and also feature 100W incandescent bulbs, adjustable hanger bars, and tri-function switches. The units are designed for installation in 2x6 joists. 800-433-1626. www.bvc.com.

American Aldes. Designed for multiple and extensive duct runs, Multi-Port Ventilators provide central ventilation for multiple baths, says the firm. MPV fan systems feature up to six exhaust points and can be remote mounted in attics, basements, or crawl spaces for quiet operation. The units also may be used for ventilation applications outside of the bathroom to address air pollution concerns in the home. 800-255-7749. www.americanaldes.com.

Therma-Stor. The Filter-Vent pairs filtration capabilities with an energy-efficient fan to distribute filtered air throughout an area. A built-in restrictor in the fresh air inlet controls the flow/exchange rate between stale air in the house and the amount of fresh air coming in. An on/off switch operates the product. A timer and charcoal filtration capabilities are optional. 800-533-7533. www.thermastor.com.