High Velocity HVAC noise - AVS Forum
Forum Jump: 
 
Thread Tools
post #1 of 11 Old 06-03-2010, 07:00 PM - Thread Starter
Member
 
Lic265's Avatar
 
Join Date: Feb 2007
Posts: 98
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 10
I have a basement room that is conditioned with a Unico high velocity HVAC system. It is noisy, and i am wondering if i should consider ripping out the ceiling and adding inline mufflers . Do they work? Other options?
Thanks
Lic265 is offline  
Sponsored Links
Advertisement
 
post #2 of 11 Old 06-03-2010, 07:50 PM
AVS Club Gold
 
Dennis Erskine's Avatar
 
Join Date: Jul 1999
Location: Near an airport
Posts: 9,136
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 1 Post(s)
Liked: 45
I doubt the mufflers will help. The issue is the "high velocity" which creates turbulence which creates noise. About all you can do is decrease the velocity by using larger ducts and larger diffusors OR more (meaning lots more) small ones.

Now to my soap box ....

I have a potential client that is very focused on specifying duct size, diffusor size, etc. Here's how it works when you're dealing with other trades (such as HVAC contractors). If your objective is to have a duct of size "x", then specify "x" if that's what is important to you. I'd suggest, that duct size is of no importance to you in an acoustic application. What is important is noise levels, etc. So if the noise level of the air leaving a diffusor is important to you then specify (as an example), the Noise Rating (or Noise Criteria) shall be not more than 21 when measured .5 meter from any diffusor.

Another example ... are you concerned that the HVAC will provide 18,000 BTU's of cooling. I'd suggest that's not what you're really interested in. Here's a better way: "The system shall maintain 70 degrees with an outside temperature range from -30 degrees to 110 degrees, humidity shall not be less than 25% nor greater than 35%...."

Let me explain one (not all) of the reasons for this. If you tell your HVAC contractor that he must meet a given temperature, humidity and NR, then if you don't get that, it is his problem to fix, at his expense, at his potential loss of license. On the other hand, if you tell him you want 10" dia. ducts, and he gives you 10" dia ducts but the air noise is outrageous and the room will get no cooler than 85, it's your problem, not his.

Think about it.

Dennis Erskine CFI, CFII, MEI
Architectural Acoustics
Subject Matter Expert
Certified Home Theater Designer
CEDIA Board of Directors
www.erskine-group.com
www.CinemaForte.net
Dennis Erskine is offline  
post #3 of 11 Old 06-04-2010, 04:00 AM
AVS Special Member
 
Terry Montlick's Avatar
 
Join Date: Jul 2003
Location: State of Rhode Island and Providence Plantations
Posts: 3,261
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 12
Good soapbox. +1.

Terry Montlick Laboratories
Home Theater Acoustics
Critical Listening Rooms
Design, Evaluation, Alpha Certification®
www.tmlaboratories.com
Terry Montlick is offline  
post #4 of 11 Old 06-04-2010, 06:10 AM
AVS Special Member
 
Elill's Avatar
 
Join Date: Dec 2007
Location: Sydney, Australia
Posts: 1,424
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 5 Post(s)
Liked: 17
Quote:
Originally Posted by Dennis Erskine View Post

Now to my soap box ....

Classic Erskine

Peter the Greek

Downunder Theatre MkII
Redefining snail pace construction
"what is worth knowing is difficult to learn"

Elill is online now  
post #5 of 11 Old 06-04-2010, 02:04 PM
AVS Special Member
 
Ted White's Avatar
 
Join Date: May 1999
Location: Midland, MI USA
Posts: 8,186
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 32
This is why he's the man

__________________

Ted



The Soundproofing Company
Ted White is offline  
post #6 of 11 Old 06-04-2010, 03:02 PM
AVS Club Gold
 
SierraMikeBravo's Avatar
 
Join Date: Mar 2007
Location: Topeka, KS
Posts: 1,395
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 4 Post(s)
Liked: 29
What Dennis doesn't know is that I designed that soapbox and rigged it to cave in at the touch of a button...he he he!

Shawn Byrne
Erskine Group
HAA Design Certified -THX Certified Professional

Design-Video & Audio Calibration Information

The original Pro Theater Layout
SierraMikeBravo is online now  
post #7 of 11 Old 06-04-2010, 03:52 PM
AVS Club Gold
 
Dennis Erskine's Avatar
 
Join Date: Jul 1999
Location: Near an airport
Posts: 9,136
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 1 Post(s)
Liked: 45
What you're really saying is you designed that soap box and it was so flimsy it caved in ... so you called it a feature not a bug.

Dennis Erskine CFI, CFII, MEI
Architectural Acoustics
Subject Matter Expert
Certified Home Theater Designer
CEDIA Board of Directors
www.erskine-group.com
www.CinemaForte.net
Dennis Erskine is offline  
post #8 of 11 Old 06-04-2010, 04:55 PM
AVS Club Gold
 
SierraMikeBravo's Avatar
 
Join Date: Mar 2007
Location: Topeka, KS
Posts: 1,395
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 4 Post(s)
Liked: 29
I can only say it is a reflection of the way I was raised in such a cruel design world.

Shawn Byrne
Erskine Group
HAA Design Certified -THX Certified Professional

Design-Video & Audio Calibration Information

The original Pro Theater Layout
SierraMikeBravo is online now  
post #9 of 11 Old 06-13-2010, 06:13 PM - Thread Starter
Member
 
Lic265's Avatar
 
Join Date: Feb 2007
Posts: 98
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 10
Ah yes, little did i know when i put in high velocity ducts that these systems dont cool/heat as effectively and are noisy. So i am bringing in some HVAC contractors, but each one gives me a different solution. Once i get all of them to give me an opinion i will post here.
Lic265 is offline  
post #10 of 11 Old 06-13-2010, 06:19 PM
AVS Special Member
 
Terry Montlick's Avatar
 
Join Date: Jul 2003
Location: State of Rhode Island and Providence Plantations
Posts: 3,261
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 12
Quote:
Originally Posted by Lic265 View Post

Ah yes, little did i know when i put in high velocity ducts that these systems dont cool/heat as effectively and are noisy. So i am bringing in some HVAC contractors, but each one gives me a different solution. Once i get all of them to give me an opinion i will post here.

This should be interesting. I doubt if Dennis and I will disagree. There are only a handful of correct solutions, and they pretty much all involve making more or larger vents.

Terry Montlick Laboratories
Home Theater Acoustics
Critical Listening Rooms
Design, Evaluation, Alpha Certification®
www.tmlaboratories.com
Terry Montlick is offline  
post #11 of 11 Old 06-25-2010, 06:53 PM - Thread Starter
Member
 
Lic265's Avatar
 
Join Date: Feb 2007
Posts: 98
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 10
Update : 2 HVAC contractors to the house. Basically they both said that the current high velocity setup will be noisy. Not too much can be improved with mufflers placed inline.
However, since the room above is the kitchen, and there is not enough cooling, one option is to take the excess capacity and put it into this space. I would then use a split unit in the medial room as a separete zone.

Not sure of the cost yet, but it does solve 2 issues - better cooling in kitchen and quieter ventilation in media room
Lic265 is offline  
Reply Dedicated Theater Design & Construction

User Tag List

Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page


Forum Jump: 

Posting Rules  
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off