New super-quiet vent fans best choice for bathroom

Cut Your Utility Bills

Q. My bathroom vent fan sounds like a Boeing 747 preparing for takeoff. Although it isn’t as efficient as a vent fan, I open the window instead. Are there any quieter and efficient methods to vent my bathroom? — G.J.

A. It is very important to ventilate your bathroom, especially when showering or bathing. In an efficient airtight house, excessive moisture quickly builds up without adequate ventilation. This can deteriorate your house and cause mold growth and allergies. Opening a window wastes a lot of heated or cooled room air.

There are several new super-quiet designs of bathroom vent fans available. One design uses a powerful axial fan that mounts in your attic. It draws air through a typical small vent grill mounted in the bathroom ceiling. The other design uses a standard ceiling-mounted vent fan with a specially-designed super-quiet fan and motor.

The sound level of vent fans is rated in units called “sones.” One sone of sound is about as loud as a new very-quiet refrigerator. For comparison, a sound level rating of six sones is twice as loud as three sones. The actual energy efficiency of the fan motor is similar for most models.

An attic-mounted axial fan is most quiet. Its sound rating is about 2.5 sones at the fan itself in the attic. However, in your bathroom, you just hear the squish of moving air. You can also use two ceiling air inlets, one over the shower and one over the sink, both connected to the same fan.

New standard ceiling-mounted super-quiet bathroom vent fans are specially designed and constructed. These quiet fans (as low 1.5 sones) usually have slower motors and are better-balanced than standard vent fans.

You can write to me for Utility Bills Update 360 showing manufacturers, model numbers, sound levels, and air flow capacities (cfm) for attic-mounted and ceiling-mounted super-quiet bathroom vent fans, and recommended air flow capacities for various-size bathrooms. Please include $1 and a self-addressed stamped business-size envelope. Send to James Dulley, 6906 Royalgreen Drive, Cincinnati, Ohio, 45244.

James Dulley studied energy management at the doctoral level at Harvard.