Dust and Noise

[George Katele]

I'm in the process of setting up a new shop in my home. It's about 16 by 25, and it's a room in the lower level of a walkout of a house set on a slope. Adjacent to the shop are a family room, and stairs leading upstairs to the main living level.

Obviously Dust and Noise (D&N (TM)) are an issue.

First of all the Dust:

I have a 2hp dust collector that will be set up at each workstation (router table, tablesaw, chop saw, etc) with appropriate ducting. I also have a ceiling hung filter. I have heard of a system that takes the shop air and vents it outdoors via a filter, and then a heat exchanger returns the air to the shop (so I'm not cooling/heating the backyard). has anyone heard of such a device, and how much will it cost?

Noise:

Shop is below master bedroom/great room area. I'm ripping up the ceiling and walls of the shop for wiring purposes, and I'm going to re-drywall. As long as the studs/joists are bare, what can I do for noise?

Thanks in advance,

George

[mitch]

Dust - you've got it covered pretty well - that's kinda a joke.

Sound - do a google search for "sound isolation systems" (include quotes). Just read the text at this site:

an overall veiw of what needs to be done. Basically, it's: mass dampens vibrations (sound waves), breaking connections hinders transmission of vibrations.

-or- call a home theater installer and pick his brain.

Mitch

[Luigi Zanasi]

On Mon, 14 Jul 2003 22:22:19 -0500, George Katele queried:

What I did for my psychologist wife's basement office is the following. The office is below the living room and next to the garage:

Ceiling: Stuffed the cavity between the joists with fiberglass insulation (and I mean stuffed, packed in tight)

Attached metal sound bar (aka resilient channel) to the joists

Screwed on 5/8 drywall (taped the joints)

Put in an acoustical tile suspended ceiling 5" below the drywall

It works well. The only sounds that get through are low frequency, such as my heavy tread on the hardwood floor above.

Luigi Replace "no" with "yk" twice in reply address for real email address

[Steve Knight]

this is a mistake. air space is the best thing you can have to help stop sound. dead air space is very effective.

[Luigi Zanasi]

On Wed, 16 Jul 2003 05:48:59 GMT, Steve Knight scribbled

Hi Steve,

I hate to disagree with you, but you might want to refer to any number of research studies, reports and manuals on this issue, for example from the Canada Mortgage and Housing Corporation (Kanuckistan's equivalent to HUD):

the sentence (under "Findings"):

"Performance can be improved by increasing the thickness and density of the insulation."

or:

did get my information from reputable sources (like CMHC manuals) and from building inspectors I was working with when I built the office.

BTW, I think I got the plane today. I got a parcel notice & I'll go pick it up tomorrow. Thanks.

Luigi Replace "no" with "yk" twice in reply address for real email address

[George]

The purpose of the insulation is to provide lots of dead air spaces. The smaller the spaces, the more likely to "eat" the sound waves rather than allow them to pass through or transfer by medium vibration.

What insulates in heating/cooling applications is the air, not the fibers.

[George SA]

George

Have a look at the following site which has quite a lot of info in connection with dust collection.

George SA

[Steve Knight]

when I mean dead air space I don't just mean one space. remember all the sheetrock and studs are tied together and transmit sound. Yes I know about it because I studied acoustics when I was a recording engineer. one of the primary sound deadening methods is to build two walls that don't touch.

[Steve Knight]

O

even better to build two walls that don't touch. yes I do know about it I did a fair amount of study about it when i was a recording engineer. dead air is very effective but it has to be done right. it takes more then one layer. but sound will not penetrate very may layers of material if they can't interact with each other with anything other then air. so yes one hollow all will not do anything but two will do great or layers of insulation that does not touch each other will work great too. it's the separation between them the dead air space between them that does the job.

[Steve Knight]

well I got the info when I was a recording engineer. where studios were built with two walls. sound was a battle and far better tested then in houses. You want dead air space several layers of it. but in a regular wall or floor the wall itself will transmit sound. there are things that absorb sound too. but the dead air space is the most effective and cost effective method. If you want a few books on it just holler I can see if I can still find them. it was something I used to be really interested in and read quite a bit of it. "Adding more insulation, or denser insulation improves acoustic performance, however it is not significant without resilient channels." A quote from the site. dead air space is very good but not easy to achieve. If you could have several separated layers of insulation in the floor over one stuffed piece it would work better.

>

[Robert Bonomi]

Well, yes AND *no*, applies.

There are two separate issues with regard to how sound (mechanical energy) carries. 1) energy transmission _within_ a particular material 2) enerty transfer _between_ two dissimilar materials

Transmission _within_ any material is more efficient than "across the boundary" to a dissimilar material.

_Within_ any material, losses increase with the _distance_ the energy must travel. Introduce a long twisted path, with lots of dead-ends, and the energy losses go _way_ up.

Those two facts are why products like styrofoam and foam-rubber are such effective sound "insulation". *LOTS* of air-plastic interfaces that attenuate the energy. And any path "just through the plastic" is _far_ longer than the "straight line" distance through the foam. Also, lots of 'false paths', where a fair part of the energy ends up going 'sideways', or even 'backwards', rather than 'through' the material.

Another effective technique for isolation involves using _lots_ of small objects, rather than a single large one. Irregularly shaped small objects work best. This -maximizes- the surface area for contact with 'dissimilar' material (e.g. the surrounding air), _and_ *minimizes* the contact area with 'like' material. Thus the sound passes 'moderately efficiently' through that _small_ contact area, spreads out in the next object, and only the small part of the energy that reaches where -that- object contacts other objects is passed on.

Sand is an amazingly effective isolator in this respect. Styrofoam "peanuts", "popcorn", etc, are also highly effective. 'sheet' in- sulation is good for this, too. Fiberglas bat is significantly less effective, because the 'rigidity' is much lower (closer to that of air). It's definitely better than an 'unfilled space', but inferior to some of the 'higher density' filler materials.

Of course, *nothing* beats a hard vacuum.

[Steve Knight]

nope. I was a flop I had no clue about music. what the hell is a riff? I could not talk to musicians.

[Leon]

LOL.. Hence you now build magnificent hand planes....

A close friend married Owen Bradley's nephew. IIRC his nephew mixed KD Lang's earlier recordings at Owen Bradley's studio in Nashville. If you G___ a S___... :~)

[Robert Bonomi]

*everybody* knows what a riff is -- it's the second half, the 'raff' that those 'so-called' musicians have _real_ trouble identifiying. *snicker*