Requirments
EXHAUSTO air handling units must be fitted with sound insulation in the duct system in accordance with the applicable sound regulations for the premises and the surroundings.The duct system should also be insulated for sound, thermal loss and condensation.
Sound output levels are used as a basis for calculating the sound pressure levels in the units operating area and the levels of silencing required in the duct system.
| KW: | Correction factor for calculating the sound output in Octave |
| KWA: |
Correction factor for calculating the A-weighted sound output Only VEX100 and VEX200 |
| KpA: | Correction factor for calculating the A-weighted sound pressure |
| LW: |
Sound output level dB Reference 1 pW Tolerance ± 3dB |
| I: |
Upper operating area |
| II: |
Middle operation area |
| III: |
Lower operating area (Only in some cases - see graph) |
| LW1: |
Lower operating area (Only in some cases - see graph) Measured as per ISO 5136 LW1= LWA1 + KW LWA1 read |
| LW2: |
Sound output level to duct (supply air / exhaust air) Measured as per ISO 5136 LW2= LWA2+ KW LWA2 read |
| LW3: |
Sound output level to the surroundings. |
| LpA3: |
Sound pressure dB (A) at 1 meter from the edge of the VEX (see measurement setup) at the hemispherical sound dissipation in free field and with insulated connecting ducts. For VEX100 and VEX200: LpA3= LWA1+KpA LWA1read For VEX300: LpA3= LWA3+KpA LWA3read |
Calculation Example VEX100
VEX170-1-FC LWA1 - Suction Side
VEX170-1-FC LWA2 - Pressure Side
|
Unit VEX170-1-FC Desired output qv = 1800 l/s (6500 m³/h) and pt = 250 Pa |
Readings: Readings respectively LWA1 (suction ducts) and LWA2 (pressure ducts) on the graph. LWA1: 73 in Area I (marked red in diagram) LWA2: 85.5 in Area I (marked red in diagram) |
Suction side (outdoor air / Extract air)
| Waveband | 63 | 125 | 250 | 500 | 1K | 2K | 4K | 8K |
| LWA1 | 73 | |||||||
| Correction factor KW (LW1) read in the graph | 6 | -3 | -3 | 2 | -5 | -17 | -24 | -33 |
| Sound output level suction side LW1 | 79 | 70 | 70 | 75 | 68 | 56 | 49 | 40 |
Sound output level (suction side)
| Waveband | 63 | 125 | 250 | 500 | 1K | 2K | 4K | 8K |
| LWA2 | 85,5 | |||||||
| Correction factor KW (LW2) read in graph | -7 | -11 | -8 | -3 | -3 | -9 | -13 | -21 |
| Sound output level pressure side LW2 | 78.5 | 74.5 | 77.5 | 82.5 | 82.5 | 76.5 | 72.5 | 64.5 |
Surroundings (Sound output)
| Waveband | 63 | 125 | 250 | 500 | 1K | 2K | 4K | 8K | dB(A) |
| LWA1 | 73 | ||||||||
| Correction factor KW (LW1) read in graph | 10 | 2 | -9 | -10 | -17 | -24 | -30 | -36 | -9 |
| Sound output level surroundings LW1 | 83 | 75 | 64 | 63 | 56 | 49 | 43 | 37 | 64 |
Surroundings (Sound pressure level)
| Weighting | dB(A) |
| LWA1 read in area I | 73 |
| Correction factor KpA(LW3) read in graph | -26 |
| Sound output level surroundingsLpA3 | 47 |
Measuring positions VEX100
Calculation Example VEX200
VEX250 LWA1 - Suction Side
VEX250 LWA2 - Pressure Side
|
Unit VEX250 Desired output qv = 900 l/s (3240 m³/h) og pt = 250 Pa |
Reading: Readings respectively LWA1 (suction ducts) and LWA2 (pressure ducts) on the graph. LWA1: 67,5 in Area I (marked red in diagram) LWA2: 81 in Area I (marked red in diagram) |
Suction side (outdoor air / Extract air)
| Waveband | 63 | 125 | 250 | 500 | 1K | 2K | 4K | 8K | |
| LWA1 | 67,5 | ||||||||
| Correction factor KW (LW1) read in the graph | 9 | 0 | -4 | 3 | -13 | -17 | -24 | -39 | |
| Sound output level suction side LW1 | 76.5 | 67.5 | 63.5 | 70.5 | 54.5 | 50.5 | 43.5 | 28.5 | |
Pressure side (Supply air / Exhaust air)
| Waveband | 63 | 125 | 250 | 500 | 1K | 2K | 4K | 8K |
| LWA2 | 81 | |||||||
| Correction factor KW (LW2) read in the graph | -2 | -10 | -12 | 0 | -6 | -9 | -16 | -26 |
| Sound output level pressure side LW2 | 78.5 | 74.5 | 77.5 | 82.5 | 82.5 | 76.5 | 72.5 | 64.5 |
Surroundings (Sound output)
| Waveband | 63 | 125 | 250 | 500 | 1K | 2K | 4K | 8K | dB(A) |
| LWA1 | 67,5 | ||||||||
| Correction factor KW (LW1) read in the graph | 2 | -6 | -15 | -19 | -23 | -28 | -33 | -37 | -16 |
| Sound output level surroundings LW1 | 69.5 | 61.5 | 52.5 | 48.5 | 44.5 | 39.5 | 34.5 | 30.5 | 51.5 |
Surroundings (Sound pressure level)
| Weighting | dB(A) |
| LWA1 read in area I | 67,5 |
| Correction factor KpA(LW3) read in the graph | -32 |
| Sound output level surroundings LpA3 | 35.5 |
Measuring positions VEX200
Calculation Example VEX300
VEX340H LWA2 - Suction Side
VEX340H LWA2 - Pressure Side
VEX340H LWA2 - Sorroundings
|
Unit VEX340H Desired output qv = 500 l/s (1800 m³/h) og pt = 250 Pa |
Reading: |
Suction side (outdoor air / Extract air)
| Waveband | 63 | 125 | 250 | 500 | 1K | 2K | 4K | 8K |
| LWA1 | 58 | |||||||
| Correction factor KW (LW1) read in the graph | 18 | 8 | -11 | 1 | -12 | -20 | -25 | -32 |
| Sound output level suction side LW1 | 76 | 66 | 47 | 59 | 46 | 38 | 33 | 26 |
Pressure side (Supply air / Exhaust air)
| Waveband | 63 | 125 | 250 | 500 | 1K | 2K | 4K | 8K |
| LWA2 | 77,5 | |||||||
| Correction factor KW (LW2) read in the graph | -1 | -5 | -5 | -2 | -5 | -7 | -15 | -27 |
| Sound output level pressure side LW2 | 76.5 | 72.5 | 72.5 | 75.5 | 72.5 | 70.5 | 62.5 | 50.5 |
Surroundings (Sound output)
| Waveband | 63 | 125 | 250 | 500 | 1K | 2K | 4K | 8K |
| LWA3 | 52 | |||||||
| Correction factor KW (LW3) read in the graph | 20 | 13 | 1 | -6 | -8 | -12 | -17 | -21 |
| Sound output level surroundingsLW3 | 72 | 65 | 53 | 46 | 44 | 40 | 35 | 31 |
Surroundings (Sound pressure level)
| Weighting | dB(A) |
| LWA3 read in area I | 52 |
| Correction factor KpA(LW3) read in the graph | -15 |
| Sound output level surroundings LpA3 | 37 |
Measuring positions VEX340H
last updated 2-14-2011
