Dear Jim: Our bathroom vent fan is as loud as Tony Stewart’s No. 20, so we seldom run it. We need a new superquiet efficient one with a light. What is the quietest type and what is best for the kid’s bathroom? – Chad Y.

Dear Chad: Most people don’t realize how important it is to run a bathroom vent fan for healthy indoor air quality and for lower utility bills. Just opening a bathroom window is not nearly as effective and it is too easy to forget and leave it open.

The key to healthy and efficient operation of a bath vent fan is running it for the proper length of time to adequately remove moisture and odors. If you run it too long, it draws excessive heated or cooled air from your house. If you run it too little, mold, fungus and wall material damage may occur. The fan motor itself does not typically use much electricity.

There are several quiet bathroom vent fan options from which to choose.

The quietest designs use a remote fan that is mounted in the attic so the sound is isolated from the bathroom. Several ceiling registers can be ducted to the same fan so it can vent the bathtub and toilet areas at the same time.

Although the ceiling register, with or without a built-in light, looks like an ordinary vent fan, all you hear is the slight “whoosh” sound of the air. Since there is no electricity connected to the ceiling register itself, there is no safety risk in mounting it in a shower stall. An optional lighted register operates on safe 12 volts for use in the shower if needed.

Another option is to install a superquiet standard vent fan in the ceiling. These use special sound-absorbing materials and blade-housing designs to minimize noise. Some are as quiet as only one sone (unit of sound). A one-sone sound is the equivalent of a very quiet human whisper. The noise specifications in sones should be listed on the packaging.

Also consider the style of vent fan. Many of the quietest ones also have the most features and are most decorative. Some very attractive ones use frosted or beveled glass on the light with real oak trim to hide the vents.

For the best efficiency, special bathroom vent fans are available with automatic controls so they run the proper length of time. These are also ideal for the children’s bathroom because they generally forget to turn the vent fan off if they use it at all. Some also have built-in night lights.

You can select the type of automatic sensor (all have a manual override) you prefer. A motion sensor, a humidity sensor or both can start the fan and light automatically. The on time can be adjusted from five to 60 minutes.

Write for (instantly download – www.dulley.com) Update Bulletin No. 877 – buyer’s guide of 11 quiet bathroom vent fan-light manufacturers (60 models) listing air flow, sound levels, features, pictures, prices, and a recommended sizing chart. Include $3 and a business-size SASE, and send to James Dulley, 6906 Royalgreen Drive, Cincinnati, OH 45244.