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Recommended
Specifications
for SOUNDSCREEN® Acoustical Panel SystemsIndustrial
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General
Double-wall
(insulated) acoustical enclosures shall be provided as specified on drawings.
All panels and components shall be prefabricated and supplied by a nationally-recognized
manufacturer with published standards of construction, assembly, and technical
performance. The manufacturer shall have produced a standardized, prefabricated
panel system for at least 10 years. Construction and performance of the
installed system and components shall conform to all specifications listed
in this document. |
Joint
Construction
Enclosure panels
shall have either a snap-lock joint construction or a tongue-and-groove
joint construction. Panels with snap-lock joint construction shall be such
that adjacent panels are held together rigidly with an integral, continuous
self-locking joint on both inside and outside panel surfaces. Panels with
tongue-and-groove joint construction will be held together with fasteners
such as screws. Neither panel types should require H-connecotrs, tape, or
any other type of additional connectors. |
Panel
Construction
| 1.
All enclosure panels shall be 2 or 4 inches thick, as noted on the
drawings, with a solid galvanized steel exterior shell, and a solid
or perforated interior galvanized steel shell as noted on the drawings. |
| 2.
The outer and inner shells shall be tack or spot welded to perimeter
and internal longitudinal steel channels and box-end internal closures,
in such a manner and spacing that the panel assembly will not fail
at the maximum operating loads specified in Structural Performance. |
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3. The outer shell shall be constructed of galvanized steel
with a minimum 18-gauge thickness. |
| 4.
The inner shell shall be constructed of galvanized steel (solid or
perforated) with a minimum 22-gauge thickness. |
| 5.
Perforated material shall have a 23 percent open area. |
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6. All perimeter and internal longitudinal steel channel members
shall be constructed of ASTM Type A-653 commercial-quality galvanized
steel with a minimum 18-gauge thickness. |
| 7.
All steel panel surfaces, internal channels, and trim items shall
be fabricated from zinc-coated steel with a dipped galvanized coating
(minimum G-60 coating with class as determined by ASTM A-924) and
shall meet all requirements of ASTM A-653 for commercial-quality galvanized
carbon steel. |
| 8.
Each enclosure panel shall be completely filled with acoustical/thermal
insulating material that is noncombustible, inert, mildew-resistant,
and vermin-proof. Insulation shall not settle within the enclosure
panel. No insulating materials shall be used that have a flame spread
greater than 25 or a smoke developed greater than 50. |
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Components
and Installation
| 1.
All base channels shall be installed on a level concrete curb, the
dimensions of which shall be determined from plan-view shop drawings
of the system provided by the system manufacturer. Spacing of base
channel attachments shall be as outlined in the manufacturer's standard
details of assembly. |
| 2.
All assembly trim items shall be constructed of hot-dipped galvanized
steel (minimum 18-gauge thickness) and furnished in standard lengths
to be field cut to the required dimensions. Spacing of sheet metal
screws, application of duct sealant, and positioning of trim shall
be in accordance with the manufacturer's published erection and installation
details. |
| 3.
For enclosures to be installed outdoors, joints and trim shall be
sealed with UNI-WEATHER solvent-based duct sealant that is a neoprene-phenolic
mastic formulated to withstand temperatures from -20°F to +300°F.
Sealant shall be formulated such that surface preparation of solvent
cleaning is not necessary. Sealant shall have a UL Classification
marking with a flame spread of 5 and smoke developed of 0 when applied
to 18-gauge galvanized steel and a flame spread of 5 and smoke developed
of 5 when applied to inorganic reinforced cement board, both at a
coverage of 53 square feet per gallon. Sealant shall exceed 1,000
hours under ASTM-D572 test conditions (oxygen bomb) without becoming
brittle and 500 hours in QUV accelerated-exterior-aging apparatus
without degradation (under ASTM-C732 test conditions). |
| 4.
Acoustical personnel access doors shall be provided where specified
on drawings and shall be 24 inches wide by 60 inches high unless otherwise
indicated. All doors shall be the same nominal thickness as the adjacent
panels. All access door panels and doors shall be constructed with
an 18-gauge solid inner and outer shell. Each door shall have a minimum
of two ball-bearing hinges and two wedge-lever door latches or panic/passage
hardware. Doors shall seat against neoprene gasket materials, installed
around the entire perimeter of the door frame in such a manner that
door operation will provide direct compression with no sliding action
between the door and gasket. |
| 5.
Where shown on drawings, acoustical doors shall be furnished with
windows, which are composed of double-glazed layers of wire-reinforced
tempered glass, separated by an air space, and sealed against acoustical
and air leakage by interior and exterior rubber seals. Windows shall
be 12 inches wide by 12 inches high unless otherwise indicated. |
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Structural
Performance
| 1.
The entire enclosure shall be designed by the manufacturer to be self
supporting. Where roof spans and wall loadings require additional
structural strength, it shall be provided by heavier panel skins,
additional internal longitudinal reinforcing members, or additional
structural members and necessary supporting pipe columns. |
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2. Under the conditions specified in the previous section,
the assembled structure shall not exhibit any panel joint deflections
in excess of L/200, where L is the unsupported span length of any
panel section within the completed enclosure. |
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Acoustical
Performance
| 1.
The manufacturer shall provide certified testing data obtained from
an acoustical laboratory, listing sound absorption and transmission
loss characteristics of the enclosure. When requested by the engineer,
the manufacturer shall arrange to have a copy of all pertinent acoustical
laboratory reports forwarded directly from the laboratory to the engineer. |
| 2.
When tested according to ANSI/ASTM C423 or a subsequent version of
the standard, the enclosure shall have minimum sound absorption coefficients,
as shown in the table below, in the 1/3 octave band center frequencies.
The coefficients used shall be those reported by the acoustical laboratory. |
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Sound
Absorption Coefficients
|
| Octave
Band (Hz) |
125
|
250
|
500
|
1,000
|
2,000
|
4,000
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NRC
|
|
4-inch panel construction |
0.63
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1.09
|
1.17
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1.08
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1.03
|
0.97
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1.09
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| 2-inch
panel construction |
0.22
|
0.64
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1.06
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1.06
|
0.98
|
0.87
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0.94
|
| 3.
When tested according to ASTM E90 or a subsequent version of this
standard, the enclosure panel shall have minimum airborne sound transmission
losses in the combined full octave band center frequencies as listed
below: |
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Sound
Transmission Losses
|
| Octave
Band (Hz) |
125
|
250
|
500
|
1,000
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2,000
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4,000
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STC
|
| for
4-inch panels |
19
|
27
|
40
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53
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58
|
63
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40
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| for
2-inch panels |
19
|
21
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30
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40
|
49
|
51
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34
|
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Thermal
Performance
| 1.
Insulating materials used in all prefabricated enclosure panels shall
have the following maximum thermal conductances at a mean temperature
of 75°F: 0.06 BTU per hour per square foot per °F (for 4-inch
panels) and 0.12 BTU per hour per square foot per °F (for 2-inch
panels). |
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