Noise suppression in ductwork? Minimum segment length?

Posted by Steve on October 23, 2009, 7:43 pm

I still stand by my original statement...

>> If you want to correct the noise issues, then you need to insure that the
>> ducts are correctly sized (Manual D duct calculation) and installed.
>> 900fpm is a bit much for RA. Correct the ductwork issues, and the noise
>> will go away.
>> Flex duct is *NOT* the way to go. find a contractor that is going to do
>> it right, not just cheap.

Its not about the lengths of the ducts, I can make an airhandler in a hall
closet with a central return almost completely silent. Its about correct
sizing and proper installation. Having installed systems in a TV station
studio, and a recording studio, its all about correct design, sizing, and
installation for proper airflow.....It also helps to use the right
materials, and flex duct ain't it.

>> You sound like an EE that hired the lowest bidder. sorry bout your luck.

> Yep, I'm an EE. But I've probably had more formal education in
> thermodynamics and physics than most people.
> It's a long story, but I didn't have any choice of contractor.
> And the cost of the upgrade was ZERO, so I can't complain about getting
> what I paid for.
> All I wanted was some engineering advice from someone in the know
> so I could make knowledgeable input to the process.
> Bitching about each other is not helpful to me.
> I need somebody smart and experienced to give me USEFUL input
> on the question I asked about minimum duct segment lengths for optimum
> noise abatement. Making the duct segments too short may have the same
> negative impact on the airflow, but possibly less positive impact on the
> noise abatement.
> Thanks, mike

Posted by Existential Angst on October 24, 2009, 12:53 am

>I still stand by my original statement...

>>> If you want to correct the noise issues, then you need to insure that
>>> the ducts are correctly sized (Manual D duct calculation) and installed.
>>> 900fpm is a bit much for RA. Correct the ductwork issues, and the noise
>>> will go away.
>>> Flex duct is *NOT* the way to go. find a contractor that is going to do
>>> it right, not just cheap.

> Its not about the lengths of the ducts, I can make an airhandler in a hall
> closet with a central return almost completely silent. Its about correct
> sizing and proper installation. Having installed systems in a TV station
> studio, and a recording studio,

You mean the one where all the recordings have that background <whoosh> and

low freq rumble? THAT was you?
Figgers.

Once again, zero help, zero information, but BIG pats on yer own back.
Figgers.

'Course, the OP didn't seem too thrilled with my advice, either.
But lessee, I *gave* advice (fwiww), and you gave, uh, what?? Oh yeah, your
recording studio, that's right....

But sheeit, make a duct thick enough and heavy enough, and it WILL be quiet.
--
EA

its all about correct design, sizing, and

> installation for proper airflow.....It also helps to use the right
> materials, and flex duct ain't it.

>>> You sound like an EE that hired the lowest bidder. sorry bout your luck.

>> Yep, I'm an EE. But I've probably had more formal education in
>> thermodynamics and physics than most people.
>> It's a long story, but I didn't have any choice of contractor.
>> And the cost of the upgrade was ZERO, so I can't complain about getting
>> what I paid for.
>> All I wanted was some engineering advice from someone in the know
>> so I could make knowledgeable input to the process.
>> Bitching about each other is not helpful to me.
>> I need somebody smart and experienced to give me USEFUL input
>> on the question I asked about minimum duct segment lengths for optimum
>> noise abatement. Making the duct segments too short may have the same
>> negative impact on the airflow, but possibly less positive impact on the
>> noise abatement.
>> Thanks, mike

Posted by Bennett Price on October 24, 2009, 1:45 pm

Perhaps this site (and links there) may help
http://www.engineeringtoolbox.com/noise-reduction-silencers-d_81.html

Posted by spamme0 on October 25, 2009, 2:58 am

Bennett Price wrote:

> Perhaps this site (and links there) may help
> http://www.engineeringtoolbox.com/noise-reduction-silencers-d_81.html

Thank you.

Your response is characteristic of what the web should be.

It appears that you:
1) Actually read the question...UNDERSTOOD the question.
2) Thought about the question before you started typing.
3) Provided information DIRECTLY RELATED TO SOLVING MY PROBLEM
and with sufficient context to be believable/useful.
3) Presented in a lucid manner.
4) Refrained from making unfounded assumptions and aspersions.
5) Refrained from name-calling, bickering and other inciting statements.

If only a few of the newsgroup denizens followed your example,
the web would be a lot better place.

I believe your input will lead to the solution to my problem.

Thanks, again,
mike

Posted by American Eagle on October 25, 2009, 3:32 am

spamme0 wrote:

> Bennett Price wrote:

>> Perhaps this site (and links there) may help
>> http://www.engineeringtoolbox.com/noise-reduction-silencers-d_81.html

>
> Thank you.
>
> Your response is characteristic of what the web should be.
>
> It appears that you:
> 1) Actually read the question...UNDERSTOOD the question.
> 2) Thought about the question before you started typing.
> 3) Provided information DIRECTLY RELATED TO SOLVING MY PROBLEM
> and with sufficient context to be believable/useful.
> 3) Presented in a lucid manner.
> 4) Refrained from making unfounded assumptions and aspersions.
> 5) Refrained from name-calling, bickering and other inciting statements.
>
> If only a few of the newsgroup denizens followed your example,
> the web would be a lot better place.
>
> I believe your input will lead to the solution to my problem.
>
> Thanks, again,
> mike

Oh Goody. Another Numbnuts that wants to dictate free speech.

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Noise suppression in ductwork? Minimum segment length? - Page 2