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tlindaas
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27th January 2012
Old 27th January 2012
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Gear nut
 

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Air flow resistivity for Isover Sweden

With the exception of the Marine products, the air flow resistivity numbers here are calculated, not measured, which mean they are more approximate than usual. The basis of the calculations are certain production parameters, and the calculations were done by a research engineer at Isover Sweden, which emailed the results to me.

Note: Some products are declared with a range of densities. When the engineer calculated the numbers, she used the lowest density in the range as one of the many parameters in the flow resistivity calculation.

Terminology: Air Flow Resistivity (in swedish: luftflödesmotstånd) is given in kPa*s/m2.

– Air flow resistivity is the same as gas flow resistivity (GFR).
– Pa*s/m2 is the same as Rayls (5000 Rayls is 5000 Pa*s/m2 , or 5 kPa*s/m2).

I use the terms "air flow resistivity" and "kPa*s/m2" because this is the terminology used in the technical documentation I have read.

The products are sorted according to their air flow resistivity value, lowest numbers first.


Products with density and air flow resistivity data:

Isover Piano Ljudskiva
Density: 13-15 kg/m3
Air Flow Resistivity: 7 kPa*s/m2
http://www.isover.se/produkter/produktvisning?id=20785
http://www.isover.se/produkter/produktvisning?id=20984
http://www.isover.se/produkter/produktvisning?id=20787

Note: This product is declared with an air flow resistivity of 6 kPa*s/m2 (on the web page). According to the measurement and publication standard EN 13162 (used by Isover) it is required for the manufacturers to publish the lowest measurement of sound absorption and air flow resistivity:

4.3.11 Sound absorption
"[…] No result of ap and aw shall be lower than the declared level."

4.3.12 Air flow resistivity
"[…] The value of air flow resistivity shall be declared in levels with steps of 1 kPa·s/m3. No test result shall be lower than the declared value."

Link: EN 13162

So, the manufactureres have several measurements of a product's air flow resistivity, and publish the lowest number. I've talked to both Isover and Rockwool tech support but no one seems to know how wide this range of measurements typically is.

Isover Cleantec Plus
Density: 35 kg/m3
Air Flow Resistivity: 7 kPa*s/m2
http://www.isover.se/installationer/...sover+cleantec

Isover ULTIMATE Piano
Density: 13-15kg/m3
Air Flow Resistivity: 10 kPa*s/m2 (declared 9)
http://www.isover.se/produkter/produktvisning?id=21062
http://www.isover.se/produkter/produktvisning?id=21067

Note: When a product comes in both a "normal" and an "ultimate" version, the ultimate version have somewhat higher air flow resistivity than the normal version, even though the products have the same density.

Isover Cleantec G35
Density: 35 kg/m3
Air Flow Resistivity: 12 kPa*s/m2
http://www.isover.se/installationer/...sover+cleantec

Note: See good bass absorption data for its sister product G100 at page 15 here:
http://www.isover.se/files/Isover_SE...onskanaler.pdf

Isover U Marine Roll MFN
Density: 24 kg/m3
Air Flow Resistivity: Equal to, or more than 12 kPa*s/m2
http://www.isover.se/produkter/produktvisning?id=22668
http://www.isover-technical-insulati...e85fd2dc6f.pdf

Isover U Marine Roll MFA
Density: 24 kg/m3
Air Flow Resistivity: Equal to, or more than 12 kPa*s/m2
http://www.isover.se/produkter/produktvisning?id=22724
http://www.isover-technical-insulati...e85fd2dc6f.pdf

Isover U Marine Slab MPG
Density: 24 kg/m3
Air Flow Resistivity: Equal to, or more than 12 kPa*s/m2
http://www.isover.se/produkter/produktvisning?id=22743
http://www.isover-technical-insulati...ac280a8426.pdf

Isover Stålregelskiva 36
Density: 16-19 kg/m3
Air Flow Resistivity: 13 kPa*s/m2
http://www.isover.se/produkter/produktvisning?id=20945
http://www.isover.se/produkter/produktvisning?id=20773
http://www.isover.se/produkter/produktvisning?id=20770
http://www.isover.se/produkter/produktvisning?id=20871
http://www.isover.se/produkter/produktvisning?id=20971

Isover Träregelskiva 36
Density: 16-19 kg/m3
Air Flow Resistivity: 13 kPa*s/m2
http://www.isover.se/produkter/produktvisning?id=20772
http://www.isover.se/produkter/produktvisning?id=20776
http://www.isover.se/produkter/produktvisning?id=21465

Isover UNI-skiva 36
Density: 16-19 kg/m3
Air Flow Resistivity: 13 kPa*s/m2
http://www.isover.se/produkter/produktvisning?id=20778

Isover U Marine Roll MFV
Density: 36 kg/m3
Air Flow Resistivity: Equal to, or more than 15 kPa*s/m2
http://www.isover.se/produkter/produktvisning?id=22727
http://www.isover-technical-insulati...e85fd2dc6f.pdf

Isover U Marine Slab MPN
Density: 36 kg/m3
Air Flow Resistivity: Equal to, or more than 16 kPa*s/m2
http://www.isover.se/produkter/produktvisning?id=22697
http://www.isover-technical-insulati...ac280a8426.pdf

Isover UNI-skiva 33
Density: 20-35 kg/m3
Air Flow Resistivity: 18 kPa*s/m2
http://www.isover.se/produkter/produktvisning?id=20841

Isover U Marine Slab MPA
Density: 48 kg/m3
Air Flow Resistivity: Equal to, or more than 25 kPa*s/m2
http://www.isover.se/produkter/produktvisning?id=22740
http://www.isover-technical-insulati...ac280a8426.pdf

Isover U Marine Wired Mat 66 Alu1
Density: 66 kg/m3
Air Flow Resistivity: Equal to, or more than 48 kPa*s/m2
http://www.isover.se/produkter/produktvisning?id=22687
http://www.isover-technical-insulati...38872db51f.pdf

Isover U Marine Wired Mat 66 N
Density: 66 kg/m3
Air Flow Resistivity: Equal to, or more than 48 kPa*s/m2
http://www.isover.se/produkter/produktvisning?id=22685
http://www.isover-technical-insulati...38872db51f.pdf

Isover Fasadskiva 31
Density: 50-60 kg/m3
Air Flow Resistivity: 55 kPa*s/m2
http://www.isover.se/produkter/produktvisning?id=21008
http://www.isover-technical-insulati...ac280a8426.pdf



Products with density values:

Isover Light Träregelskiva 39
Density: 13-15 kg/m3
http://www.isover.se/produkter/produktvisning?id=20943

Isover Bjälklagsskiva P 36
Density: 16-19 kg/m3
http://www.isover.se/produkter/produktvisning?id=20774

Isover ULTIMATE UNI-skiva 37
Density: 16-19 kg/m3
http://www.isover.se/produkter/produktvisning?id=20780

Isover ULTIMATE Stålregelskiva 37
Density: 16-19 kg/m3
http://www.isover.se/produkter/produktvisning?id=21050

Isover ULTIMATE Träregelskiva 37
Density: 16-19 kg/m3
http://www.isover.se/produkter/produktvisning?id=21021

Isover Duo 33
Density: 20-35 kg/m3
http://www.isover.se/produkter/produktvisning?id=20817

Isover Installationsskiva 33
Density: 20-35 kg/m3
http://www.isover.se/produkter/produktvisning?id=21019

Isover Skalmursskiva 33
Density: 20-35 kg/m3
http://www.isover.se/produkter/produktvisning?id=22547

Isover Stålregelskiva 33
Density: 20-35 kg/m3
http://www.isover.se/produkter/produktvisning?id=20958

Isover Träregelskiva 33
Density: 20-35 kg/m3
http://www.isover.se/produkter/produktvisning?id=20930

Isover Fasadboard 33
Density: 120-125 kg/m3
http://www.isover.se/produkter/produktvisning?id=20764




How to interpret density values:

There is a relationship between density and air flow resistivity, but it is loose, very non-linear. Generally, denser products means higher air flow resistivity, but with the same density, glass wool products will typically have higher air flow resistivity than stone wool products, and there are large variations in the density/flow resistivity correlation within these two main product groups, generated by other factors. A very rough understanding of the relationship between density and air flow resistivity can be derived from density/flow resistivity correlation graphs provided by the manufacturers. I have these numbers from Rockwool, Isover, and from an independent Norwegian construction research institution (Byggforsk):

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

Note: The graphs are hard too read with any accuracy, so don't take the numbers too seriously. But if you are interested in this, there are more information in the graphs than in the numbers displayed here. Be aware that when a manufacturer estimates the performance of competing products, it will be portrayed as "bad" as reasonably possible.


Links to graphs:

Rockwool:
Rockwool flow resistivity/density correlation graph
Rockwool Marine & Offshore Acoustic Manual (page 23)

Isover:
Isover flow resistivity/density correlation graph (page 9)

Byggforsk (older, unspecified Nordic insulation products):
Byggforsk flow resistivity/density correlation graph (page 6)


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If you have other acoustic data, relevant for Sweden, please share.