Bathroom Vent Fans Can Be Quieter and More Efficient
QUESTION: Our bathroom vent fan sounds like a Boeing 747 at takeoff. I want to replace it with a new efficient, quiet vent fan. How can I tell which fans are the quietest and how large a fan do I really need?
ANSWER: There have been many recent design improvements in bathroom vent fans for more quiet and efficient operation. Many of the new super-quiet ceiling-mounted and remote in-line models are difficult to hear at all.
In any house, it is extremely important to adequately ventilate the bathroom. Running a vent fan is more efficient overall than just opening a window. Excessive moisture can quickly deteriorate your house and exacerbate mold growth and allergy problems.
New convenience features also make replacing an old vent fan a wise move. One Smartsense model has a built-in humidity sensor to automatically switch it on and off. It has a motion sensor to automatically turn on the light plus a built-in night-light. Manual override switches are included.
Since most vent fans look alike, compare the sound-level specifications. Sound level is rated in “sones.” The quietest models rate only 0.5 sones, about as loud as a quiet whisper. The box should list the sones rating.
Internal design features make the difference between a noisy and a quiet fan. Special sound absorbing scrolls and flexible motor mounts reduce noise. Just the design of the interior air chamber has a major effect.
It is also very important to size the vent fan properly for quiet operation. Don’t just buy a big expensive one. No matter how well it is designed, a vent fan with a larger air flow capacity will be louder.
As a rule of thumb, the air flow capacity (in cubic feet per minute--cfm) of a bathroom vent fan should be about 10% greater than the square footage of the bathroom. A 50-square-foot bathroom needs a 55-cfm vent fan.
Installing a remote in-line vent fan is a quiet and effective option. The fan, sometimes called a tube fan, is mounted up in the attic. It is attached with flexible dryer duct to a grill in the bathroom ceiling.
Since the fan motor is located away from the bathroom, it is very quiet. By using a T-duct fitting, one in-line fan can vent two areas simultaneously--two separate bathrooms, or above the sink and in the shower stall. A low-voltage fan/light unit is the only other safe option for the shower itself.
If you absolutely do not have access to vent the bathroom outdoors, install a ventless ceiling or wall fan. These have special built-in filter elements.
Write for Update Bulletin No. 761 showing a buyer’s guide of 13 super-quiet bathroom vent fans listing air-flow capacities, sound levels, features, prices and a sizing chart. Please include $2 and a business-size self-addressed, stamped envelope and mail to James Dulley, Los Angeles Times, 6906 Royalgreen Drive, Cincinnati, Ohio 45244. To rush bulletin delivery, e-mail: https://www.dulley.com.
New Gas Furnace May Use More Electricity
Q: I recently installed a new high-efficiency gas furnace. It provides very comfortable heat, but my winter electric bills seem to be higher now. Would the new furnace use more electricity?
A: A new high-efficiency gas furnace may use somewhat more electricity to operate the blower than your old one. This is because older furnaces were often sized way too big, so they did not have to run as much.
A properly sized furnace runs more, but since it uses less gas, the overall gas and electric savings are significant. Also, by running longer, comfort and indoor air quality are greatly improved.
Old Attic Can Use Leftover Insulation
Q: I had a room added to my house. It was built efficiently with extra insulation. Is it important to have the same insulation level in the attic over the old section too? There is insulation left over.
A: It is not critical to have the same insulation in your entire attic. Generally, the more the better. Even if you cannot cover the entire attic floor over the old rooms, cover as much of it as you can.
Unfaced batt insulation is best to use for the second layer. If the leftover insulation has a vapor barrier, cut slits in it with a knife. Otherwise, it can trap moisture between the old and new layers.
