Bathroom fans: strong, silent types.(Buyers Guide)

Although an exhaust fan has been a standard part of most bathrooms for many years, people are often loath to use theirs, thinking it's too noisy. That's unfortunate because, as this report explains, it's important to keep indoor moisture levels down, especially in newer, more airtight homes. And as our tests of 20 fans show, a good one doesn't have to be raucous. The best were affordable, easy to install, and nearly inaudible.

HOW TO CHOOSE

Estimate the air-moving capacity you need. The Home Ventilation Institute, the industry's trade association, has this sensible rule of thumb for most bathrooms: The fan should have airflow of one cubic foot per minute (cfm) for every square foot of bathroom area up to 100 square feet. For larger bathrooms, the institute recommends a ventilation rate based on the number of fixtures present--50 cfm for each toilet, shower, or bath and 100 cfm for whirlpool tubs. A large bathroom may need two smaller fans, not one large one.

Most fans on the market carry a cfm rating from the Home Ventilation Institute. Our tests show that you can rely on those numbers. Only the bottom-rated fan didn't come close to its cfm rating.

Look for a quiet fan. We measured each fan's noise in decibels. The quietest ones whispered. The noisiest produced a noticeable hum.

Our findings track with the industry's noise ratings, which you can use to compare fans. The industry bases its ratings on a sones scale, which represents how people perceive loudness. As the sones number doubles, so does the loudness. Fans we judged excellent for noise typically have an industry rating of 0.5 to 1.2 sones. Fans we judged very good typically have an industry rating of 1.5 to 2 sones. The noisiest we tested are rated at 4 sones.

Mind the drafts. Most fans will try to prevent outside air from entering the room. A few were worse than the norm. Drafts will be most noticeable ff the weather is severe in your area.