Healthy alternatives to foam or rock/glass wool

[jamesblonde]

I'm ready to build some large sound absorption panels for my home (in several rooms) but rather than using 'acoustic foam' or rock/glass wool I would prefer to use something more natural with no VOCs, lung-irritating fibres, etc.



I found an interesting article about healthier alternatives in SOS magazine but the article is already a bit out of date and there was no performance comparison of the options listed: The Green Studio



Does anyone know of a group test comparing some of the greener options such as sheep wool, hemp, coconut fibre, etc? Ideally the material should be fire and insect resistant.



FWIW, I'm planning to build some cloth-covered frames around 1.2m high, 2m long and 10cm deep to house the 4-7cm of insulation plus a modest air gap between the insulation layer and the wall. Something like this:

 

[Galu]

Don't know of any comparative tests, but sheep wool insulation seems to have many advantages e.g. as well as offering 'outstanding' sound insulation, it resists bursting into flame.

A great thing about sheep wool is that it doesn’t burn; it is just about the only fibre that naturally resists flaming and as soon as the flame is removed it will actually self-extinguish.
As a result of the wool’s high nitrogen content, it will simply smoulder and singe away instead of bursting into flame. In fact you will need to heat the wool to a temperature in excess of 560°C before it burns.

The advantages of sheep wool insulation - TheGreenAge

For anyone interested, here is a UK supplier: thermafleece environmentally friendly acoustic infill for stud walls

 

[Pano]

Yes to sheep's wool, very good indeed. But $$$$

In North America there is UltraTouch by Bonded Logic. It performs about the same as fiberglass in the higher resisters. better in the low end.
We also have a sort of spun wood panel that I can never remember the name of that has been found in schools for 70 years. I don't remember seeing it in Europe.
Coconut fiber would be cool if it lasts.

FWIW, I built a set of panels using fiberglass and they worked very well. The upholstery fabric I used to cover them was so thick there wasn't any chance of the fiberglass getting out. There is a thread about them here somewhere.

 

[jamesblonde]

Thanks, I was already leaning towards the sheep's wool. It might be pricey but I only need around 6m2.

 

[Pano]

Sheep's wool is pretty much the ultimate.

This company makes all sorts of natural fiber insulation, but they don't seem to have any specifications.
ENKEV

 

[Galu]

Find out what the woolly shepherd is up to!

Natural Acoustic Sound Absorbing Panels for Ceilings and Walls - The Woolly Shepherd

 

[mhenschel]

https://www.gni.ca/user_files/upload/Roxul. Flexibatt.pdf

Roxul makes a "board" -- Comfortboard -- that you can cut easily and pretty cleanly with a bread knife.

Fire and vermin resistant.

Fire and Soundproofing Insulation | ROCKWOOL

 

[markbakk]

We also have a sort of spun wood panel that I can never remember the name of that has been found in schools for 70 years. I don't remember seeing it in Europe.

Oh that has been used for decades here (The Netherlands) also. Heraklith is wood fiber, has excellent sound absorption, is cheap and readily available. My basement ceiling is completely covered with it, excellent high frequency absorption, sadly no air gap, as it was placed there as fire retardant.

 

[Galu]

Roxul makes a "board" -- Comfortboard -- that you can cut easily and pretty cleanly with a bread knife. Fire and vermin resistant.

Mineral fibre with cured urea extended phenolic formaldehyde binder? Doesn't sound 'green' to me!

 

[markbakk]

By the way sheep’s wool isn’t that green either. And posing that natural fibers are healthier than artificial ones seems way too simple to me.

 

[mhenschel]

@galu
From the FAQ"

FAQ Frequently Asked Questions | ROCKWOOL

"Standard ROCKWOOL products do currently use a phenol formaldehyde binder during production. During manufacturing, the binder is cured at very high temperatures leaving only trace amounts in the product after it is produced. ROCKWOOL AFB®, SAFE’n’SOUND®, and COMFORTBATT® have all achieved GREENGUARD GOLD status for indoor air quality.

ROCKWOOL also offers a no added formaldehyde product, AFB evo™, starting July 1st 2017. This product is produced with a new formaldehyde free binder, and retains all of the properties of the original AFB® product."

https://cdn01.rockwool.com/siteasse...ical-fire-batts-techdata.pdf?f=20200422073435
https://cdn01.rockwool.com/siteasse...rmaldehyde-free-techdata.pdf?f=20190515124416

@Pano
I think the name that escaped you also frequently escapes me: Tectum
TECTUM Direct-Attach Wall Panels | Armstrong Ceiling Solutions – Commercial

 

[Pano]

Tectum, yes. Thank you. I'll remember it for about a week.

 

[JLOP]

Recycled Cotton wool is excellent, called ‘Métisse here in France.

 

[454Casull]

Cellulose or recycled denim insulation are options as well.

 

[Pano]

Ultra Touch is recycled denim. It does work well. Very even across the spectrum, which is nice. Seems to be better in the low end than fiberglass of mineral wool. Similar to sheep's wool, IIRC.

 

[jamesblonde]

For anyone interested, here is a UK supplier: thermafleece environmentally friendly acoustic infill for stud walls

Their price for a 75 x 370 x 8500mm roll of Cosywool is an astonishing £65.62


I found the same product and size at Celtic sustainables for £24. I hope that helps some of our UK members. (see Thermafleece - Cosywool Sheeps Wool Insulation )



Unfortunately it doesn't help me as they don't ship to Italy due to the bulk and weight.

 

[JLOP]

Ultra Touch is recycled denim. It does work well. Very even across the spectrum, which is nice. Seems to be better in the low end than fiberglass of mineral wool. Similar to sheep's wool, IIRC.

Hi Pano, indeed excellent, some measurments here La mesure des coefficient d'absorption, in French but the graph speaks by itself

Jean-Louis

 

[Pano]

Wow! Nice measurements. Cotton does do well in the lower frequencies
Ah, les Français aiment toujour le parois sablé.

 

[markbakk]

Remarkable, DIY absorption measurements! The impedance tube is a good approach, be it such measurements are only valid for sound propagating perpendicular to the plane.

 

[jamesblonde]

It's very reasonably priced too. METISSE M+ - Panneau acoustique laine de coton - Acheter au meilleur prix