ASA Apecial session on HVAC noise control sans fibres.

Angelo Campanella acampane at postbox.acs.ohio-state.edu
Sun Jun 25 13:41:51 EST 1995


                 ** CALL FOR PAPERS **

ON HVAC SYSTEM NOISE REDUCTION WITHOUT THE USE OF FIBROUS MATERIALS
               ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
FOR PRESENTATION AT THE 130th MEETING OF
THE ACOUSTICAL SOCIETY OF AMERICA
IN ST. LOUIS, MO SOMETIME DURING 27 NOV-3 DEC 95.

BACKGROUND AND RATIONALE:

For two important reasons, we need to review and report the progress
-to-date of noise reduction methods in HVAC mechanical systems without
the use of fibrous materials.  I'll dispense quickly with the first
and perhaps superficial reason..

1/ There has been some talk - largely informal - that opinions on
glass fibres could take a turn toward that held for asbestos.  To
date, there has been no convincing evidence of cancer manifestations
for fiberglass as commonly used.  The primary inferences have their
origin in animal experiments involving mega-doses of glass fibres
injected into rather unlikely parts of animals...  But also none of us
enjoy the "itching" syndrome encountered in handling open batts of
fiberglass.

2/ More importantly, fibrous materials - including organic fibre
replacements for inorganic fibres - readily accumulate and harbor
dust, spores and microbes.  The latter can survive and multiply given
the right moisture conditions, to then propagate through ducts
and vents into occupied spaces.  Thus, mildew and respiratory ailments
can result... contributing to what has come to be known as the "sick
building" syndrome.  In addition, ducts and silencers lined with
fibrous materials require added cleaning and maintenance. In addition, 
organic materials add fire propagation and fumes in duct.

Thus the latter facts provide a compelling long-term need for
permanent noise reduction materials and components which do not rely
on organic or inorganic fibres as the acoustic flow resistant element.

Long-standing methods are already available such as perforated metal
plates, wire screens and compliant plenums.  A noted advance in the
promulgation of accumulated knowledge has bee Prof. Uno Ingard's
recent "Notes on Sound Absorption Technology" (Book and software,
distributed by the Noise Control Foundation, P.O. Box 2469 Arlington
Branch, Poughkeepsie, NY 12603).  Included are design methods for
sound absorbers via porous screens and cavities and in ducts.

=======

SO................. In concert with these notions and trends, a
special session on "NOISE CONTROL OF MECHANICAL SYSTEMS WITHOUT THE
USE OF FIBROUS MATERIALS" is being conducted at the 130th meeting of
the Acoustical Society of America in St. Louis, MO, somewhere between
27 Nov and 3 Dec, 1995.

WHAT IS SOUGHT at this time are noise control engineers and HVAC
component designers who are willing to share their experiences by
preparing and presenting a paper on the design and the performance of
noise control products without the use of fibrous materials.

Please E-Mail me (acapmane at magnus.acs.ohio-state.edu) your comments
and intentions immediately if you are interested in participating.

The customs and procedures of ASA are that on or before 31 July, 1995,
an abstract (200 words or less) is to be sent to the Meeting technical
chair in St. Louis (copy to me - the session organizer).
I can help you get this done...


Ang. Campanella.  14:17 25 Jun,1995


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