Rectangular Duct Attenuators - RS / RT Series

  Features
  • These notes apply to RS and RT type attenuators

  Construction
  • The units are rigidly constructed and consist of a galvanised sheet metal casing containing a series of centre and side splitters.
  • The casing is provided with Pittsburgh corner seams.
  • End flanges have a red oxide finish and are not drilled as standard unless ordered with matching flanges.
  • The splitters are filled with no hygroscopic and incombustible material.
  • This material is covered with a gauze scrim and then further covered with galvanised perforated sheet metal.
  • Where attenuators are exposed to the weather, all infill material shall be lined with an impervious film to prevent ingress on moisture.
  • See page G-6 for selections from our Q-Seal range.
  • Standard attenuators are suitable for duct pressures up to 1kPa.
  • Attenuators suitable for higher pressures or manufactured from special materials such as stainless steel or aluminium, are available on request.
  • In addition, special finishes such as epoxy coating can be provided.

Insertion Loss
  • The values quoted in the tables are defined as static insertion loss as defined in BS4718:1971, Methods of Test for Attenuators for Air Distribution System.
  • Insertion losses greater than 50dB are not reported as their achievement in practice is difficult.
  • The performance data is based on Australian-sourced and manufactured materials.

  Suggested Specification
  • Attenuators shall be as manufactured by Elta Fans and shall have the performance as scheduled.
  • The casing shall be manufactured from high quality galvanised mild steel sheet with Pittsburgh corner seams.
  • Mild steel end flanges shall be provided pop-riveted and sealed to the case.
  • These shall be finished with zinc-rich primer or hot dipped galvanised after fabrication if requested.
  • Acoustic splitters shall have a semi-circular inlet fairing with tapered discharge profile to minimise pressure drop and regenerated noise, like Q-Tech RT series.
  • Where nominated, straight splitter attenuators can be used like Q-Tech RS series.
  • Airways shall be straight and parallel.
  • The infill material shall be either rockwool or fibreglass as specified by the manufacturer.
  • The infill material shall be covered with a gauze scrim to prevent erosion of the fibres, then encased in galvanised perforated sheet metal Where attenuators are exposed to the weather they shall be of the Q-Seal type.
  • All infill materials shall be lined with an impervious film to prevent the ingress of moisture.
  • The infill material when tested in accordance with AS1530.3:1989 shall have the following indices: -
          - Ignitability 0
          - Spread of flame 0
          - Heat evolved 0
          - Smoke developed 0

  Performance

Performance Data - RS Straight Splitters
    Static Insertion Loss, dB  
  Length Octave Band |Centre Frequency (hz) Module
Model RS..  mm 63 125 250 500 1k 2k 4k 8k widths, mm
07B 900 6 12 23 36 45 43 36 28 275 550,
825, 110,
1375, 1650,
1925, 2200

Free Area 27%
07C 1200 8 16 30 47 50 50 47 39
07D 1500 9 19 35 49 50 50 49 42
07E 1800 10 21 41 50 50 50 50 45
07F 2100 12 25 45 50 50 50 50 50
07G 2400 13 28 48 50 50 50 50 50
10B 900 5 10 19 31 39 35 27 21 300, 600,
900, 1200,
1500, 1800,
2100, 2400

Free Area 33%
10C 1200 6 13 26 41 48 46 37 26
10D 1500 8 16 30 47 50 50 43 31
10E 1800 9 18 35 49 50 50 48 36
10F 2100 10 20 40 50 50 50 50 37
10G 2400 11 23 44 50 50 50 50 39
12B 900 4 9 17 28 35 31 22 17 325, 650,
975, 1300,
1625, 1950,
2275

Free Area 38%
12C 1200 5 11 22 37 43 40 30 21
12D 1500 6 13 26 43 47 44 34 24
12E 1800 7 15 31 47 50 48 40 28
12F 2100 8 17 35 50 50 50 43 30
12G 2400 9 20 39 50 50 50 45 32
15B 900 4 8 15 25 31 28 18 13 350, 700,
1050, 1400,
1750, 2100

Free Area 43%
15C 1200 5 9 19 33 38 34 23 16
15D 1500 5 11 23 39 44 39 26 18
15E 1800 6 13 27 45 49 46 32 21
15F 2100 7 15 31 49 50 50 37 24
15G 2400 8 18 35 50 50 50 41 26
 
 
 

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