[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: GSBN:Re: STC of Straw bales



G 'day One and All

In some pain RSI of the elbow too much rendering and typing.  Need a secretary!

Anyway for what it is worth here is a copy of our testing on sound for a two string straw bale wall that we built some moons ago in Sydney.

The Straw Wolf

G' Day One and All

We have just completed testing (at least three years ago now!)
the sound qualities of "The Practice
Pad".  The Practice Pad consists of three sound recording studios in
Surry Hills, an inner Sydney Office and Residential area, that we built
two years ago for Bruce Thomas.  The Studio is located on the third
floor of a 6-storey office block.  There are five straw bale walls 450
mm thick (18") which were sheeted in Gyprock 10mm on a 4x2 timber stud
wall.  Each room has a double cavity door 450 mm deep no windows and a
wall mounted air conditioner.

The University of Technology Sydney kindly lent me the equipment to
measure the sound levels.  We need these results for the College of
Sustainable Building (Straw Panel Factory) that we will build in 99 (03 now ) in
Ganmain in the middle of the village.  The walls of the College will be
900mm (3') thick, the machinery in the factory (college) will consist of
a very large band saw run by an electric motor solar powered.

The tests on The Practice Pad were carried out by myself with a couple
of witnesses, no cheating was allowed.  The instrument was a Radio Shack
Sound Level Monitor made in China under a Canadian licence, does that
make it Canadian?  I used two weighting's in the tests in the studio and
these were:

Weighting A curve frequency of 500-10,000 Hz range
      "   C   "       "      " 200-18,000  "   "   I think need to
confirm the C however the C frequency is for musical instruments and the
A for humans I think.

Anyway the results are as follows:   The three studios were in full
operation and three very loud bands were using the studios at the time
of the recordings:

Inside Studio 2 Background Noise Level                  A 55 db

(No Bands Playing)                                      Air Con 61 db

                                                        C 54 db

                                                        Air Con 61 db

Outside Studio 2 Background Noise Level                 A 58-62 db

(No Bands Playing)                                      C 63-68 db

Inside Studio 2, One Very Loud Band Playing             C 114-117 db

Outside Studio 2, Three Very Loud Bands Playing         A 62 db

        (Meter 12" from walls)                          C 71 db

Outside Studio 2 Three Very Loud Bands Playing          A 60-62 db

        (Meter 10' from walls)                          C 67-68 db

Outside Studio 3 All Bands Playing                      A 65-66 db

        (Meter under the air con)                       C 75-78 db

There was sound travel coming from the air con from Studio 3 from all
the other studios.  (This a problem Bruce has to rectify.)
Outside the window Street Noise Levels                  A 68-71 db

                                                        C 68-70 db

Therefore it can be said that the straw bale walls are very effective in
reducing sound as if you all did not know that anyway.  I just have not
been able to get any figures anywhere so here they are for what they are
worth.  It was a very scientific testing conducted with meter in hand
and an ale in the other. (Only joking).

I also tested some other well-known noise producers whilst I was in
Sydney.  I used the A frequency.

Inside a house that I was staying in at Sydeneham Background 51 db

                                        Jumbo Overhead       82 db

                                        Jumbo Outside       104 db

It was interesting to see how some Sydneysiders have to live!

On the M5 Freeway  104-109 db

On Parramatta Road   83-102 db

Salaams Straw Wolf
http://strawbale.archinet.com.au