Air out bathroom with rebuilt or new vent fan

Q My old bathroom vent fan sounds like a low-flying jet, and it does not seem to draw very well. I need a new quiet one that is also efficient. How should I go about selecting a new vent fan for the bathroom?

A: Some inexpensive bathroom vent fans are noisy right out of the box. If your old fan was quiet years ago, you may be able to repair it. Remove the cover and unplug it. Clean out all the dust and tighten all the screws. Just a loose screw or two can create an annoying, loud sound.

Bathroom fan rebuilding kits are available for many of the economy fans that builders often install. A kit costs less than $50 and takes only about 15 minutes to install. It includes a new quiet-design motor, multiple motor plates to adapt to many models and an updated grille. When installed, the fan can be as much as 50 percent quieter than the old one when it was new.

If you decide you really need a new bathroom fan, there are some ultra-quiet ones available. Most of these fans have all the newest features for convenience and energy conservation. They are so quiet that running one at night when using the bathroom should not wake anyone else in your house. You can expect to pay up to several hundred dollars for this type of fan.

Before you start looking at new bathroom fans, it is important to select the proper cfm (cubic feet per minute of air flow) size. A fan with a lower cfm rating is generally quieter than a larger one with the same design and features. The sound level of a bathroom fan is rated in sones, and this should be listed in the packaging. Ones with a 6-inch duct, instead of a standard 4-inch one, usually are quieter.

If you select a bathroom fan that is too small, it may not be able to vent the excess moisture or odors from the bathroom fast enough, if at all. If one is too large, it will be noisier and waste electricity. A general guideline is 1.1 cfm of air flow capacity is needed for each square foot of bathroom floor area.

You also have to decide what basic design of bathroom fan you need: fan only, fan/light, fan/light/heater, or fan/light/night light. Each has its advantages, and the prices vary significantly. You will also find various fan controls: simple on/off wall switch and motion- or humidity-sensing.

The most effective and efficient bathroom fans use humidity-sensing controls. These come on automatically at a high humidity level, such as after showering, and shut off automatically. This is ideal for children's bathrooms because they tend to forgot to turn off the fan. These models also include manual controls.

The following companies offer bathroom venting products:

--Broan/Nutone, 800-558-1711, www.broan.com.

--Continental Fan, 800-779-4021, www.continentalfan.com.

--Fantech, 800-747-1762, www.fantech-us.com.

--Hunter, 888-830-1326, www.hunterfan.com.

--Panasonic, 800-211-7262, www.panasonic.com.

Send inquiries to James Dulley, The Post and Courier, 6906 Royalgreen Drive, Cincinnati, Ohio 45244 or visit www.dulley.com.