COPYRIGHT 2016 JAMES DULLEY ( www.dulley.com/sea/ ) - November 2016 - (graphics ref. No. 208 at www.dulley.com/sea/column/2016-nov.htm )

"How to select and size a super-quiet bathroom vent fan for efficiency, humidity control, indoor air quality"

Dear Jim: My old bathroom vent fan is noisy and does not remove humidity well. Is there any difference in new fan efficiency and how do I find choose a quiet one? Can I install a new one myself? - Sandi T.

Dear Sandi: With the proper selection of a new bathroom vent fan, there can be significant improvement in overall efficiency and reduced noise. Replacing a bath vent fan is not a difficult project. Some models are designed with multiple duct adapters and brackets for simple installation.

Before running out to the home center store to get a new one, you may be able to improve the function and lower the noise level of your old one. Often just a thorough cleaning of the inside, especially the blade surfaces, increases its air flow and decreases the noise.

To be extra safe, switch off the circuit breaker to the vent fan. Unscrew the grill and the motor mounting screws to get full access. Clean every surface you can reach including up into the duct as far as possible with an alcohol wipe.

Even if the motor bearings are a little worn, cleaning may bring it back into balance and reduce air flow resistance. Another option is to get a lower-cost fan rebuilding kit with just a new motor and blade. This will bring it back to its original efficiency and sound level, but not as good as brand new one.

The sound level of a vent fan is rated in "sones" and is listed on the packaging. The quietest fans are only 0.3 sones, but any under 1.0 are very quiet. At this level, you can barely hear it running. A smaller (meaning less air flow) fan is typically quieter than a large one of equal quality.

To determine the size vent fan your need, the HVI (Home Ventilating Institute, www.hvi.org) recommends 1.1 cfm (cubic feet per minute) of air flow for each square foot of bathroom floor area. When installing a multispeed fan, make sure the maximum air flow rating meets this.

There are differences in the efficiencies of bathroom vent fan designs. To be Energy Star certified, a small fan must vent at least 1.4 cfm/watt-used and a larger fan (90 cfm and larger) must be twice that efficient.

Although the above fan efficiency is somewhat important, the type of fan control has a much greater impact on your utility bills. If a fan runs longer than necessary, it obviously wastes electricity and draws out excessive conditioned air.

If the fan runs too little or is too small, excess moisture builds up indoors. This can make the air conditioner run longer, affect your comfort, exacerbate allergies, and damage windows and building materials.

A combination motion-sensing and moisture-level-sensing control with a multispeed fan motor and a LED light is by far the best. If the moisture level is not excessively high, the motion sensor will start when you enter the bathroom and stop when you leave it (you may adjust the stop delay).

When showering and creating much moisture, the moisture sensor keeps the fan running after you leave the room until the level drops. The best sensors detect a rapid rise in moisture level and automatically switch the fan to high speed. It goes back to quieter low speed and then stops.

Another super-quiet option is an efficient in-line vent located in the attic. Ducts from the powerful fan can run to two separate inlet grills  such as one over the sink and one over the bathtub. It is compatible with any type of sensor and control.

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.net; Hunter, (888) 830-1326, www.hunterhomecomfort.com; and Panasonic, (800) 405-0652, www.panasonic.com.

Dear Jim: My neighbor is a cleaning nut. She even cleans off the light bulbs in her lamps and claims it saves electricity. Is there really any point to dusting light bulbs? - Brian G.

Dear Brian: Your neighbor may not be the nutty one in your neighborhood. A layer of dust on a light bulb can reduce the light output by up to 20 percent. This may force you to switch an additional lamp.

Gently wipe off each light bulb with a damp cloth every several weeks. Unplug the lamp before wiping it. Make sure the bulb has been off for at least five minutes so that it is cool or the glass may crack.

Send inquiries to James Dulley, Publication Name, 6906 Royalgreen Dr., Cincinnati, OH 45244 or visit www.dulley.com.