# Fred # wrote:
Wife purchased three of the quiet Broan QT080L bathroom exhaust fans with
light and night light. I tested it out on the kitchen table and it was quiet
so then I proceeded with the installation in the downstairs 1/2 bathroom.
The bathroom is down to studs and subfloor with all insulation removed for
remodel. The Broan has a 4" duct connection but the house has 3". Once
everything was connected, the fan wasn't all that quiet. The noise was from
both fan vibration and wind. Its still more quiet than the old noisy fan
but I could hear the new fan from upstairs. The mounting is solid to joist
per instruction and the connection to the 3" duct is tight. I suppose once I
close up the ceiling and walls with insulation it would not be as bad. Are
quiet fans really all that quite? Maybe should have purchased Panasonic fans
instead - its the same price.


I was unable to find the specs for the model you metntioned

QT080L

maybe a letter is missing from the model number?

in any case..........one of the design features of the quieter fans is
the use a a larger duct size.

The quiet ones use a 4" duct & the really quiet ones use a 6"
duct....to keep the air velocities & the back pressure on the fan low.

By using the exisitng smaller duct you are negating some of the quiet
fan's benefit.

Addtioning most of the quiet fans have some sort of resiliant mounting
system...does yours have that & is it working?.....hard mounting allows
more sound to be transmitted through the framing.

cheers
Bob