TP wrote:
We have a booster fan built-in to a 8 inch round duct. This was
needed for the long run, 50+ foot. It has a rheostat for speed
adjustment. Seems to move the air just fine at 60% of full
power. Problem is the noise. When the air is moving the noise
travels to all the rooms. We did replace it, thinking the first
one was defected. Does anyone know of a quiet booster fan?

Thanks,
TP

I wanted to add that locating the duct fan well away from the supply and
close to the destination would reduce the noise to other areas other than
the one being served by that specific duct.

I will also add that if there is any other solution, like a better or
larger duct or improved duct distribution design and the elimination of the
fan, that may be the best method.

--
Joseph Meehan

26 + 6 = 1 It's Irish Math