On Aug 15, 9:54*am, "HeyBub" wrote:
Robert Green wrote:
I want to truly silence my Hayden central vac. *I bought a muffler
for it, but it's not really of much use since I've already vented the
exhaust to the outside via an unused dryer vent. The facts are that
it's a high RPM motor and it whines and wakes people up when it's in
use when someone's sleeping. My plan is to box it inside something
lined with acoustical foam and to provide two auxilliary fans (one
low mounted push, one high mounted pull and thermal monitoring) to
keep the motor cool and shut if off if the temperature in the box
gets too high. *I know the motor's got a built in thermal shutoff,
but since I am going to be running it in an abnormal environment and
what a replacement costs, I'd feel safer with two.

I am going to make some preliminary and crude sound measurements
wrapping in a different material to see if any has particularly good
sound deadening properties. *Anything I am missing? *What sort of
materials (I was thinking 3/4" ply and that bumpy acoustic foam)
should I use? *How much distance to leave around the unit for good
airflow? *What CFM rate? *What sized fans? *I intend to use 120MM 12V
PC case fans, but I'm worried that a lot of sound will leak out
through the fan ports. *I thought perhaps "top hatting" them the way
chimneys and vent pipes are covered would reduce the leakage,
especially if the cap had some acoustical foam facing the fan.

Any thoughts appeciated. *Any flames will be cheerfully ignored!

You may be trying to solve the wrong problem.

I'd put a timer on the electrical input so they thing won't even WORK during
sleeping hours.

There's also an innovative fix involving three items: Pliers, blowtorch, and
the person running the vacuum.- Hide quoted text -

- Show quoted text -

Yea blowtorch the person running it at 2am