Hoval RoofVent CON-9, Design Handbook

Page: 248 / 280

278
11 Fresh air silencer
The fresh air silencer reduces the noise from RoofVent
®
units
through the weather louvre door. It consists of an Aluzinc
cowl with sound attenuation lining and an opening in down-
ward direction. The silencer is connected by hinges to the
top edge of the unit. Please note the following:
■ Using a fresh air silencer only makes sense in combina-
tion with an exhaust air silencer of type FSD-6/110 or
FSD-9-10/110.
■ In RoofVent
®
LH and LK units, additional sound attenua-
tion splitters are installed in the fresh air chamber.
Type ASD-6 ASD-9-10
L mm 500 600
W mm 1080 1380
H mm 790 825
Weight kg 44 70
Pressure drop Pa 4 4
Table K17: Technical data for the fresh air silencer
Frequency ASD-6 ASD-9-10
63 Hz -1 0
125 Hz 1 2
250 Hz 5 5
500 Hz 5 6
1000 Hz 6 6
2000 Hz 5 6
4000 Hz 6 5
8000 Hz 4 5
Sum 5 5
Table K18: Insertion attenuation of the fresh air silencer (values in dB at standard fan
speed)
12 Exhaust air silencer
The exhaust air silencer reduces the noise from RoofVent
®
units through the exhaust air grille. It consists of an Aluzinc
casing with sound attenuation splitters. Please note the
following:
■ The exhaust air flow rate is slightly reduced by the addi-
tional pressure drop.
■ The exhaust air silencer is available in two different
lengths.
■ The exhaust air silencer is delivered in dismantled form;
please follow the assembly instructions.
Type FSD- 6/60 6/110 9-10/60 9-10/110
L mm 600 1100 600 1100
W mm 1080 1080 1380 1380
H mm 790 790 825 825
Weight kg 120 185 125 205
Pressure drop Pa 15 20 20 25
Table K19: Technical data for the exhaust air silencer
Frequency FSD- 6/60 6/110 9-10/60 9-10/110
63 Hz 4 8 6 9
125 Hz 5 9 8 12
250 Hz 9 14 11 17
500 Hz 15 22 15 22
1000 Hz 20 26 17 24
2000 Hz 19 25 19 25
4000 Hz 19 25 15 23
8000 Hz 14 22 11 17
Sum 11 16 13 18
Table K20: Insertion attenuation of the exhaust air silencer (values in dB at standard
fan speed)
Options
Fresh air silencer