"TP" wrote in message
...
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

A muffin fan is the way to go. We have a food dryer that had a 4 bladed fan
and was very noisy. I replaced with a muffin fan of same physical size. Has
same airflow and so quiet can't tell if it is running without feeling air
flow. W W