Ive Been Planning This Garage Studio for 10 Years!

#61

Oh wow, this makes so much sense! I could even mount some downlights in there as well.
I think I feel confident to move ahead now! :yahoo:

One more question - Whats your thoughts on using a fan on both the intake and exhaust vents, vs just having one on the intake?
I've heard advice that using two fans will even up the air pressure in the room, but is that really much of a consideration?

#62

yes it will make a difference for the better -- with the caveat that fans make noise - mechanical and air noise. so keep them on the far side of the silencers is key - but also consider maintenance - cleaning, replacement etc. the main reason i recommend ERV/HRV units - powerful air flow, configurable speed, and durability for continuous running, filtering and ease of cleaning, energy exchange and moisture level management, and in a single package. :-)

which can be placed away and isolated from the rest of the facility. most times the air flow is sufficient to allow placement further away than just fans.

#63

gullfo wrote:more like this: https://www.knaufinsulation.com.au/prod ... enum-liner you generally want perforations or other open-face-like absorption, the faced products will produce less resistance but not as much of the MF and HF component absorption which is highly desirable. this product may be workable: https://insulshop.com.au/product/semi-rigid-board/ but i'd be inclined to use the Knauf product.

Glenn - this and the following exchange with Jennifer is really good stuff...I'm messing around with the design of my Live Room Silencers at the moment

...however Graeme's question was one I should have asked before I did my CR silencers :oops:

- I used this

: Bradford Supertel

in my CR silencers - in part because I thought that the key feature of the silencer boxes was the cancellation with sound waves bouncing off baffles/walls AND I just couldn't get the "tissue" looking (open) faced product anywhere at the time. I should have known better - the openness of the facing falls into the same pot as the discussion about losing too much of the HF with bass trapping.

So...while not wishing to hijack Graeme's post...how bad is my error in choice of product?

#64

it will still do it's job in your case, but generally, for small systems, as long as it's not foil covered, or is perforated foil, it should be ok as a sealed surface on it could reduce its effectiveness at absorption - whereas in large systems you might want large runs to have the foil to reduce friction, in small systems, with proper fans, friction in the ducts is usually not an issue with getting the right levels of air flow.

for example, if the air handler is 10m away from the room, then it's probably not going to make much difference. if it's 3m away, then the exposed insulation (with treated anti-erosion coating) will help with higher frequency machine noises etc, and in that proximity, my ducts would also be of the absorptive kind as well, plus the plenum being made with duct board too.

#65

Thanks Glenn

Graeme - feel free to resume normal transmissions :lol:

BTW - if you end up with any duct board left over - let me know - I will need more for my Live Room silencers (and now plenums) and am in Sydney a bit over the coming months so can do a "cash and collect'
Andrew

#66

I'm having a real hard time locating anyone who has carries any of these products, and who is willing to sell me a small amount.
I only need about 15m2

The Knauff Climacoustic is unfortunately not available, anymore. In fact it seems the web page has been taken down since my enquiry! :lol:

The Fletchers Semi Rigid Board (w/ perforated foil facing) is available today but comes in minimum pack of 36m2, which will cost around $1000 AUD :ahh:

However I'm also waiting on some availability and quotes for the Bradford Flexitel Blanket.
There is an option to have it faced with 'Black Matt Facing' which is described as "A black, light duty tissue facing for budget conscious acoustic applications where the duct liner may be partially visible – non aesthetic, suitable to reduce the prominence of the duct liner only and not suitable for mechanical cleaning."
I think that sounds like a suitable facing, and fingers crossed I can get hold of a small enough amount reasonably soon...

#67

I suspect I already know the answer, but can i use Bonded Polyester Fibre safely in the vents?

I happen to have a bunch of this stuff laying around.
It doesn't have any loose fibres, and it seems to be non flammable.
However I don't know whats it absorptive properties are like, and perhaps it would go molding over the years.

Just wondering if anyone has experience with this stuff?

https://www.foamsales.com.au/products/dacron-per-meter

#68

i suspect - no. the consideration is erosion over time. constant air flow will cause things to come off and enter the air your breath. if you do want to use it, then consider a lining over it to prevent it from escaping. a thin tough plastic will work. you'll miss some of the HF absorption but it may not be a significant concern.

however, that stuff is nice to have for fill, over insulation, to give it a nicer finish under the cloth (think upholstery).

#69

I found this product that is designed as a lining to prevent fibre fall from glasswool and polyester insulation, and its only $1.60 per metre so super affordable. From its look and description, it appears to be the same type of meterial as the Matt Black Facing that Bradford use on their DuctLiners.
https://www.insulwest.com.au/shop/acoustic/black-scrim/

#70

that seems to be workable.

#71

GraGra wrote:I found this product that is designed as a lining to prevent fibre fall from glasswool and polyester insulation, and its only $1.60 per metre so super affordable. From its look and description, it appears to be the same type of meterial as the Matt Black Facing that Bradford use on their DuctLiners.
https://www.insulwest.com.au/shop/acoustic/black-scrim/

if its not - its doing a great impression

#72

GraGra wrote:Source of the post I'm having a real hard time locating anyone who has carries any of these products, and who is willing to sell me a small amount.
I only need about 15m2

The Knauff Climacoustic is unfortunately not available, anymore. In fact it seems the web page has been taken down since my enquiry!

The Fletchers Semi Rigid Board (w/ perforated foil facing) is available today but comes in minimum pack of 36m2, which will cost around $1000 AUD

However I'm also waiting on some availability and quotes for the Bradford Flexitel Blanket.
There is an option to have it faced with 'Black Matt Facing' which is described as "A black, light duty tissue facing for budget conscious acoustic applications where the duct liner may be partially visible – non aesthetic, suitable to reduce the prominence of the duct liner only and not suitable for mechanical cleaning."
I think that sounds like a suitable facing, and fingers crossed I can get hold of a small enough amount reasonably soon...

Been there

They seem to want to sell 10 sheet packets at a minimum - 2.4 x 1.5m sheets. I got a pack of 6 sheets (of old stock - before they changed to 10) "Bradford Supertel Semi Rigid Sheet with Perf Foil 32 kg - 25 mm" from Insulshop...not sure if that helps but the black or white facing is what you want - I had to settle for the foil which while perforated does not allow as much air flow as the facing you are looking at

#73

gullfo wrote:Source of the post the silencer and plenums can all be in the room when i'm designing, i typically use wall-ceiling soffits to allow me to route air, wires, lighting etc PLUS get a lot more absorption while freeing up the walls and floor spaces.
here's an example of a silencer in the soffit feeding a plenum centered over the desk. in each step there is expansion. and the return opposite would be similar with the velocity increasing as the duct / spaces contracts.

Glenn
I notice you have only 1 baffle in your silencer- does that do the job? All the ones I see seem to have 3 - or do you have some "secret sauce"?
Andrew

#74

gearjunk1e wrote:Source of the post Been there They seem to want to sell 10 sheet packets at a minimum - 2.4 x 1.5m sheets. I got a pack of 6 sheets (of old stock - before they changed to 10) "Bradford Supertel Semi Rigid Sheet with Perf Foil 32 kg - 25 mm" from Insulshop...not sure if that helps but the black or white facing is what you want - I had to settle for the foil which while perforated does not allow as much air flow as the facing you are looking at

This is what I just purchased for my own silencers. It wasnt cheap so keeping my fingers crossed that it works out well. On paper it seems right. https://www.grainger.com/product/1VDN4

#75

the example has a simple turn versus a "twisted path". technically, simply blocking a direct path should be enough - but - if you have noise in the system (machine, other rooms etc) then the extra turns expose more insulation to the flow and thus more opportunities to attenuate it. otherwise if the system is quiet, little or no adjacent noise, and the air flow is slow, you can often use less "silencer", then if you're routing the air through a ceiling soffit + plenum, the amount of noise is also attenuated in the packing around the flex (or hard) duct.
as a general principle, i use duct board whenever possible - it has many benefits of both a hard duct and flex duct in terms of attenuation, air flow, some blocking. of course it's also pricy compared to flex duct, but often is the same or less than duct liner simply because more of it's used by hvac professionals vs duct liner.

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