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© FANTECH
2016
NOISE CONTROL PRODUCTS
RECTANGULAR DUCT ATTENUATORS
R3T..
Series
RT..
Series
RT..QS
Series
R3T..
Series
RT..
Series
RT..QS
Series
R3T..
Series
RT..
Series
RT..QS
Series
32
28
24
19
RT07G RT07GQS
25
28
24
22
19
17
R3T15G
RT10G RT10GQS
22
24
22
20
17
16
R3T17G
RT12G RT12GQS
18
22
19
17
16
15
R3T22G
RT15G RT15GQS
14
19
17
15
14
13
R3T30G
RT20G RT20GQS
30
26
0
21
18
RT07F RT07FQS
24
26
23
19
17
16
R3T15F
RT10F RT10FQS
21
23
20
18
16
15
R3T17F
RT12F RT12FQS
17
21
18
16
15
14
R3T22F
RT15F RT15FQS
12
17
15
14
13
12
R3T30F
RT20F RT20FQS
27
24
18
16
RT07E RT07EQS
22
24
21
17
15
14
R3T15E
RT10E RT10EQS
19
21
19
16
14
13
R3T17E
RT12E RT12EQS
16
19
16
14
13
12
R3T22E
RT15E RT15EQS
12
16
14
12
11
11
R3T30E
RT20E RT20EQS
25
22
15
14
RT07D RT07DQS
20
22
19
15
13
12
R3T15D
RT10D RT10DQS
17
20
16
14
12
11
R3T17D
RT12D RT12DQS
14
18
15
12
11
11
R3T22D
RT15D RT15DQS
11
14
12
10
10
9
R3T30D
RT20D RT20DQS
22
19
12
11
RT07C RT07CQS
17
19
17
12
11
10
R3T15C
RT10C RT10CQS
15
17
14
11
10
9
R3T17C
RT12C RT12CQS
12
16
13
10
9
9
R3T22C
RT15C RT15CQS
9
13
11
9
8
8
R3T30C
RT20C RT20CQS
18
15
10
8
RT07B RT07BQS
14
16
13
10
8
7
R3T15B
RT10B RT10BQS
12
14
11
9
8
6
R3T17B
RT12B RT12BQS
10
13
10
8
7
6
R3T22B
RT15B RT15BQS
7
10
8
7
6
5
R3T30B
RT20B RT20BQS
14
10
6
4
RT07A RT07AQS
10
11
9
7
5
4
R3T15A
RT10A RT10AQS
9
10
8
6
5
4
R3T17A
RT12A RT12AQS
7
9
7
6
5
3
R3T22A
RT15A RT15AQS
6
7
6
5
4
3
R3T30A
RT20A RT20AQS
Length
mm
2400
2100
1800
1500
1200
900
600
%
open
area
26
33
37
43
50
26
33
37
43
50
26
33
37
43
50
26
33
37
43
50
26
33
37
43
50
26
33
37
43
50
26
33
37
43
50
Length
(F)
2100
Product Codes
Low Frequency biased noise
dB(A) reduction
General fan noise
dB(A) reduction
2
1
ACOUSTIC
PERFORMANCE
DATA
Acoustic performance tests to ISO7235-2003 that have been simplified to single digit noise reduction levels are shown in table above.
Detailed attenuator insertion loss (SIL) spectrums based on testing to the BS4718-1971 Standard can be obtained using the Fans by Fantech
Product Selection Program.
Example: How to select a rectangular attenuator
For this scenario, noise from a car park exhaust fan results in a noise level of 83dB(A) in the car park it ventilates.
The exhaust air volume passing through the fan is 7m
3
/s. The user would like to have a target noise level in the carpark of 60dB(A).
Also, the attenuator can be no longer than 2200mm long, is not exposed to the weather, and can have no more than 20Pa of air
flow resistance through it to avoid affecting the fan selection.
1
Select the appropriate noise reduction data column. Exhaust fan noise would be classified as 'General Fan noise'.
2
Choose the attenuator series required. Both the RT and R3T models would be appropriate as the internals of the attenuator
are not exposed to the weather.
3
The noise reduction required is found by subtracting the target noise level from the current noise level.
83dB(A)
Current noise level
- 60dB(A)
Target noise level
= 23dB(A)
reduction required
.
Under the “General fan noise dB(A) reduction” columns for the attenuator series (RT & R3T) chosen earlier, follow the line sequence
until the reduction noise (23 dB(A)) is found or marginally exceeds this number.
4
To achieve a 23 dB(A) noise reduction using the RT series, the following length and % open area combinations can be used;
2100mm/37%, 1800mm/33% and 1500mm/26%. For our example going forward, we will use the 2100mm long, 37% open area
option. The selection closest to the top is normally the best from a price perspective. To evaluate other options, repeat the steps from
4
onwards.
5
( )
3
H-6
4