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Common Gas Flow Resistivity numbers. Studio Monitors
Old 23rd January 2012
  #31
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Greater

Thanks Andre. It is odd that they put the figure right on the front page of a general info sheet, yet it is relatively meaningless.
I suspect that 5KRayls is the GFR of the lightest CIB, thus the other two are greater than.
I will ask them for clarification now that you have calibrated my thoughts.

Tuned, DD
Old 24th January 2012
  #32
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Good stuff

Old 24th January 2012
  #33
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Quote:
Originally Posted by Victor_Stoian View Post
according to mr. Fischer from Caruso:
ISOBOND WLG040 (20kg/m³) has about 5kPa*s/m²
ISOBOND WLG035 (45kg/m³) has about 12kPa*s/m²
I am not Dan, but thank you for the information.

Andre
Old 24th January 2012
  #34
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you're welcome!
Old 27th January 2012
  #35
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Old 30th January 2012
  #36
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Direct

Thank you for all that great work tlindaas.
May I ask a favour? Could you edit or do a new post, copying and pasting all of that info into one post here. I would be more than willing to do this for you if you wish.
My hope in starting this thread was to gather as many GFR figures as poss in the one convenient place.

I or someone else perhaps may collate some of the info sometime.
e.g present the range of GFR's for 48KG and 100KG Glass



Best, DD
Old 30th January 2012
  #37
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No problem, take whatever you need from those threads :-)
Old 30th January 2012
  #38
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Wow

I was taking a look at the links while you were writing. There is an enormous amount of data there. I will leave it alone for the moment, but thoroughly recommend those links. Again, thank you.
Amongst the mass of data we have this little gem...
Air flow resistivity ----------------------------: 5 kPa*s/m2 ------10 kPa*s/m2 ----- 20 kPa*s/m2 - ---30 kPa*s/m2 ------40 kPa*s/m2 ----- 50 kPa*s/m2
Rockwool stone wool products: ------------- : 9-31 kg/m3 ----- 24-49 kg/m3 ----- 36-75 kg/m3 ---- 47-98 kg/m3 ------ 56-120 kg/m3 --- 64 -130 kg/m3
Isover stone wool products: ---------------- : 27-40 kg/m3 --- >50 kg/m3 ---------------------------------------------------------------------------------------
Unspecified Nordic stone wool products --- : ------------------- 32-37 kg/m3 ----- 38-52 kg/m3 ---- 53-65 kg/m3 ----- 70-80 kg/m3 ----- 80-90 kg/m3
Isover glass wool products: ---------------- : 9-18 kg/m3 ----- 15-30 kg/m3 ----- 27-45 kg/m3 ---------------------------------------------------------------
Unspecified Nordic glass wool products --- : ------------------- 13-27 kg/m3 ----- 33-45 kg/m3 ---- 47-58 kg/m3 ----- 65-75 kg/m3 ----- 75-85 kg/m3

DD
Old 29th February 2012
  #39
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More

Thanks to Kaleido.

Isover Piano Ljudskiva
Density: 13-15 kg/m3
Air Flow Resistivity: 7 kPa*s/m2

Isover Cleantec Plus
Density: 35 kg/m3
Air Flow Resistivity: 7 kPa*s/m2

Isover UNI-skiva 36
Density: 16-19 kg/m3
Air Flow Resistivity: 13 kPa*s/m2

Isover UNI-skiva 33
Density: 20-35 kg/m3
Air Flow Resistivity: 18 kPa*s/m2

Isover Fasadskiva 31
Density: 50-60 kg/m3
Air Flow Resistivity: 55 kPa*s/m2

DD
Old 8th May 2012
  #40
Gear Maniac
 

Here's another addition to your list:

According to several mails with the German firm e.m.o. e.K. (schaumstofflager.de), their BASOTECT material is made by BASF and has a flow resistence of 12,4 kPa*s/m²


Here's a quite from the mail:
Quote:
According to BASF: The flow resistence of Basotect G as listed in DIN EN 29052 averages 12,4 kPa*s/m²

This would make it twice as effective as Rockwool (SONOROCK) of the German firm Rockwool.

Source link:
schaumstofflager.de
Panels are sold in 100x100 and 100x50 centimeter cuts. Custom cuts are possible, you just need to mail them. They are pricey however.


And a word of warning, they usually only go by material density, which they think is more important in acoustics than flow resistence.
Old 8th May 2012
  #41
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Quote:
Originally Posted by Mister Fox View Post
Here's another addition to your list:

According to several mails with the German firm e.m.o. e.K. (schaumstofflager.de), their BASOTECT material is made by BASF and has a flow resistence of 12,4 kPa*s/m²


Here's a quite from the mail:



This would make it twice as effective as Rockwool (SONOROCK) of the German firm Rockwool.
What do you mean "twice as effective"?
Old 9th May 2012
  #42
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Sonorock has a flow resistence of about 6kPa, BASOTECT accorting to the mail about 12,4kPa.

So if I go by plain numbers, a rockwool slab with 5cm and 6kPa flow resistence is (in theory) half as effective as Basotect with the same thickness. Or the other way around: Basotect is (in theory) twice as effective at the same thickness as Rockwool (Sonorock).


Comparision:
http://www.stanleyhallstudios.co.uk/...1=50&v21=12400

In this math example, Sonorock actually goes lower in terms of absorption than Basotect. But Basotect has a coefficient of 0,8 at about 800Hz while Sonorock reaches the same value at about 1,2kHz.


Here is a comparision with 10cm thickness (about 4"):
http://www.stanleyhallstudios.co.uk/...=100&v21=12400

Here, Sonorock reaches down to about 400Hz at 0,8 (coefficient), while Basotect is effective down to circa 320Hz.


You decide what suits your needs better. Sonorock is however more affordable than Basotect at the same thickness over here. Then again, should I decide to build a barrier matt trap/resonator, I maybe opt for Basotect instead of Rockwool.

Like in this example:
Sound on Sound StudioSOS March 2006 Bass Trap
Old 9th May 2012
  #43
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Quote:
Originally Posted by Mister Fox View Post
Sonorock has a flow resistence of about 6kPa, BASOTECT accorting to the mail about 12,4kPa.

So if I go by plain numbers, a rockwool slab with 5cm and 6kPa flow resistence is (in theory) half as effective as Basotect with the same thickness. Or the other way around: Basotect is (in theory) twice as effective at the same thickness as Rockwool (Sonorock).


Comparision:
Porous Absorber Calculator - Results

In this math example, Sonorock actually goes lower in terms of absorption than Basotect. But Basotect has a coefficient of 0,8 at about 800Hz while Sonorock reaches the same value at about 1,2kHz.


Here is a comparision with 10cm thickness (about 4"):
Porous Absorber Calculator - Results

Here, Sonorock reaches down to about 400Hz at 0,8 (coefficient), while Basotect is effective down to circa 320Hz.


You decide what suits your needs better. Sonorock is however more affordable than Basotect at the same thickness over here. Then again, should I decide to build a barrier matt trap/resonator, I maybe opt for Basotect instead of Rockwool.

Like in this example:
Sound on Sound StudioSOS March 2006 Bass Trap
The absorption properties of a porous material is determined by the flow resistivity and the depth of the absorber (and possible air gaps). A high flow resistivity does not automatically mean "better performance". Actually, if used at normal depths (about 200 mm or deeper, or you´ll just "EQ" the reflections removing the mids and highs as demonstrated by your examples); the opposite is true. Also, random incident values are not usually of interest since broadband absorbers used in studio design are primarily intended to absorb first order reflections and these arrive at specific incidence.

Common Gas Flow Resistivity numbers.-porous-absorber-200-mm.gif
Old 11th May 2012
  #44
Gear Maniac
 

If I go by your posted GIF example, the SONOROCK actually performs better at 20cm thickness compared to BASOTECT G with a higher flow resistence. It's the other way around at 10cm (here BASOTECT goes lower but has not such a high coefficient).

With all the data we have at the moment, we could in theory indeed find the right material for the right desired thickness of an absorber.

This is certainly interesting.
Old 11th May 2012
  #45
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Interesting

It certainly is. There is a specific thread focussed on fibre and gap depth and density and GFR. Q 4 Avare
This thread here was born out of that. It is meant to be a growing list of GRF figures. People have found it difficult to get actual GFR's. Those that have succeeded have been kind enough to share in this dedicated thread.

DD
Old 20th June 2012
  #46
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Johns Manville 300"L x 15"W x 9-1/4"D R-30 Fiberglass Insulation Roll

1673 rayls per meter
Tested via ASTM c 522

according to the company rep who got back to me today.
Old 20th June 2012
  #47
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Quote:
Originally Posted by Einstein View Post
1673 rayls per meter
Much different from the 6000 mks rayls/m quoted from Terry Montlick earlier. Also 5000 rayls/m seems to be a common figure quoted around here, for example in this post. It seems to me that much difference could have a big effect. Does anyone have any original sources for the 5000 or 6000 rayls/m figures? I think something like pink fluffy was mentioned in that NASA paper, but I haven't time to look it up at the moment. But given the frequency of its suggestion for LF dampers I think we should make sure we know what the number is! I'd be amazed if the Johns-Manville product were that much different from Owens-Corning.
Old 20th June 2012
  #48
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Well oddly enough, 1675 seems to be sort of a magic number according to the PAC. It's the only gfr that I can get 40Hz up to .82 by having 24" of the stuff with a 12" air gap. At least this is according to the PAC. I may build something in the next week or two and test it out with this stuff vs OC.

I mentioned this in another thread, but I'll put it here. OC has replaced most of their roll insulation with "ecotouch" and they have told me that they do not know, nor plan to test for gas flow resistivity.
Old 6th March 2013
  #49
Gear Head
 

This may well be a repost, but I received some info from Rockwool UK today, it includes a table of absorption coefficients and some GFR data.

Product Nominal Density (kg/m³) Value From Graph Air Flow Resistivity (mks rayl/m, Pa.s/m², N.s/m4)
RW3 60 ~1.3 ~28 x 10³
RW4 80 ~0.85 ~42 x 10³
RW5 100 ~0.6 ~60 x 10³
Firebatt 825 110 ~0.55 ~65 x 10

The Air Flow Resistance pdf also contains a graph which allows you to calculate GFRs for other Rockwool products.
Attached Files
Old 24th March 2013
  #50
Gear addict
can someone help me get the density and gas flow resistivity for AZ06E earthwool R2.5 HP Batts
Old 23rd April 2013
  #51
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fito 88, I don't know if this is relevant to you, but I talked to a Norwegian Knauf sales rep today who told me that in the UK they sold some DIY insulation with very low density, he was referring to Earthwool with a lambda value of 44. It is even less dense than Space slab/rolls with a lambda value of 37 and 39, and since those has a gas flow resistivity around 5 kPa, you might expect even lower values for Earthwool.
Old 7th May 2013
  #52
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Another Knauf, slightly different technology, manufactured in my country (may be used also in Bulgaria, Romania, Greece, etc.)...

Code:
Knauf KR S   GFR = 9.500 kPa*s/m², Density =  32 kg/m³
Knauf KR SK  GFR = 10.30 kPa*s/m², Density =  40 kg/m³
Knauf KR L   GFR = 13.80 kPa*s/m², Density =  50 kg/m³
Knauf KR M   GFR = 14.30 kPa*s/m², Density =  60 kg/m³
Knauf KR P   GFR = 26.00 kPa*s/m², Density =  75 kg/m³
Knauf KR T   GFR = 49.10 kPa*s/m², Density = 120 kg/m³
Knauf KR Z   GFR = 54.80 kPa*s/m², Density = 150 kg/m³
Knauf KR TF  GFR = 58.40 kPa*s/m², Density = 100 kg/m³
Knauf KR H   GFR = 116.0 kPa*s/m², Density = 180 kg/m³
Knauf KR D   GFR = 162.0 kPa*s/m², Density = 200 kg/m³
Old 17th June 2013
  #53
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BRADFORD
Building Blanket (11kg/m3) ........5600 mks Rayls/m
Multitel (18kg/m3) ...............15300 mks Rayls/m
Flexitel (24kg/m3) ...............16200 mks Rayls/m
Supertel (32kg/m3) ...............18200 mks Rayls/m
Ultratel (48kg/m3) ...............31500 mks Rayls/m

TONTINE
Acoustisorb 1 (22kg/m3 100mm)......4350 mks Rayls/m
Acoustisorb 2 (32kg/m3 100mm)......8070 mks Rayls/m
Acoustisorb 3 (48kg/m3 100mm).....14230 mks Rayls/m

FLETCHER INSULATION
Pink Partition (11kg/m3 75mm)....4050 mks Rayls/m
Pink Partition (14kg/m3 90mm)....5090 mks Rayls/m
FI 32 (32kg/m3 100mm)...........14680 mks Rayls/m
FI 48 (48kg/m3) ................untested
Old 4th April 2014
  #54
nms
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Quote:
Originally Posted by Audioactive View Post
from rockwool software

40kg/m3 = 14916 N s/m4
So this is the GFR of 2.5pcf Roxul Safe n Sound I take it?
Old 4th April 2014
  #55
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Does anyone know of a US available product that is ~2"s thick, ~60,000 mks Rayls/m, and flexible (can be rolled around into a ~10" diameter tube?). Did anyone ever find out for ultratouch?

hunting for a acoustic impedance device material for a cardioid loaded woofer...playing with porous absorber calc it looks like those numbers have at least the most even absorption coefficient over my pass band (~100-500). Thanks-
Old 4th April 2014
  #56
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Quote:
Originally Posted by nms View Post
So this is the GFR of 2.5pcf Roxul Safe n Sound I take it?
SnS is ~10,000 Rayls/m.

Andre
Old 4th April 2014
  #57
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Quote:
Originally Posted by RyanC View Post
Does anyone know of a US available product that is ~2"s thick, ~60,000 mks Rayls/m, and flexible (can be rolled around into a ~10" diameter tube?). Did anyone ever find out for ultratouch?

hunting for a acoustic impedance device material for a cardioid loaded woofer...playing with porous absorber calc it looks like those numbers have at least the most even absorption coefficient over my pass band (~100-500). Thanks-
OC703 is 48 kg/m3, and while it cant be rolled, it can be cut into rings.
Old 4th April 2014
  #58
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Pipe

Old 4th April 2014
  #59
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A large part of the pipe insulation here in the states (for commercial installation anyway) is fiberglass......... the Knauf products are available in thicknesses up to 6" depending on the pipe size..........

Rod
Old 4th April 2014
  #60
nms
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Quote:
Originally Posted by avare View Post
SnS is ~10,000 Rayls/m.

Andre
Where did you get this from? That seems really low.

Their software states 14,916 for their products with 40kg/m3 density

In the Norway thread I saw 3 rock wool products having 30kg/m3 density listed at 9000

This graph posted also puts 40kg/m3 rock wool at approx the 14,100 mark:
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