Fantech's N3T..QS series rectangular attenuators with 300mm thick
tapered splitters are available to suit a variety
of applications and duct dimensions. They can be made in
different widths and heights, and each model number denotes
a different percentage of open area and length combination.
They provide superior insertion loss and pressure drop
performance over standard rectangular attenuators.
The N3T..QS rectangular Q-Seal tapered attenuator incorporates
an infill system protected by an impermeable plastic
membrane/film.
The N3T..QS series is suitable in medical and clean room
applications and any sensitive ventilation systems requiring
an infill material that prevents the possibility of insulation fibre
ingress into the airstream.
They are also suitable where the insulation medium is directly
exposed to weather, grease, liquid, or dusts. Attenuators of this
model type may also be cleaned periodically by low-pressure
steam or pressure washer equipment.
Construction
- Casing and splitters made from Z275 coated galvanized steel.
-
Infill from bio-soluble acoustic grade glasswool or mineral wool, encased behind finely perforated galvanized steel. Infill is
hygroscopic and incombustible.
-
Standard construction rated to duct pressures between
-500Pa and +1kPa relative to atmosphere.
-
Have infill material protected by liquid
impermeable Melinex® PET Plastic Film.
Sectional Sizing and joining flange information
-
Flanges 35mm TDF or compatible up to a maximum height
or width of 1200mm. Above these sizes 40mm or 50mm steel
angle section frames used, supplied undrilled.
-
Matching flanges for attaching to accompanying ductwork can
also be supplied.
-
Rectangular attenuators will typically be made in a single piece
up to a maximum of 2250mm in width, length, or height where
practical for transportation. Above this dimension attenuators
will be split into multiple sections in the dimension(s)
exceeding the 2250mm limit noted.
-
As a special request, attenuators may be divided into smaller
sized sections than standard to fit through small spaces,
before they are reassembled as a single unit on site.
Customised attenuator options
The following are available as special options when ordering
Fantech rectangular attenuators:
-
Different materials of construction such as Stainless Steel
Grades 304 and 316.
-
Paints / protective coatings such as epoxy paint, Chlorinated
Rubber etc.
-
Flange material/dimensions profile can be specified
(e.g. Ductmate, TDF, Plain Steel Angle).
-
Access doors for easy cleaning (e.g. in Kitchen Exhaust
Applications).
Insertion loss
Static insertion loss values derived from tests to ISO 7235:2003
Acoustics
-
Laboratory measurement procedures for ducted silencers
and air-terminal units.
- Insertion loss, flow noise and total pressure loss.
- Insertion losses greater than 60dB are not reported.
Suggested specification
Rectangular attenuators shall be of the N3T or
N3T..QS Series as designed and manufactured by Fantech Pty.
Ltd. and shall have the dimensions, acoustic attenuator insertion
losses and pressure losses as scheduled. Acoustic Attenuator
Insertion Loss data for the attenuators to be derived from tests in
accordance to ISO7235:2003
The casing shall be manufactured from forming grade Z275
coated galvanised steel sheet with Pittsburgh corner seams
and 200mm or 300mm thick tapered splitters. The infill material
shall be bio-soluble acoustic grade glasswool or mineral wool.
The infill material shall be encased in galvanised perforated sheet
metal. Where attenuators are exposed to the weather, grease,
liquid, or dusts they shall be of the N3T..QS Series
where all infill materials shall be protected with an impervious film
to prevent the ingress of moisture.
The infill material when tested in accordance with AS1530.3:1999
shall have the following indices:-
Ignitability 0 Spread of flame 0 Heat evolved 0 Smoke developed 1
