SoundScoop Brochure - Passivent

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COMBINES
HIGH ACOUSTIC
ATTENUATION
WITH LOW AIRFLOW
RESISTANCE
SOUNDSCOOP
ACOUSTIC AIR TRANSFER UNIT
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CI/SfB (57) Xy
Uniclass L7535
September 2011

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SOUNDSCOOP
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SOUNDSCOOP
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ACOUSTIC
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AIR
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TRANSFER
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UNIT
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SoundScoop is a range of ventilation air
transfer units which combine exceptional
acoustic attenuation with very low airflow
resistance.
This combined performance is superior to
any existing comparable unit on the market.
Typical application
SoundScoop used as a crossventilation
path between two spaces
receiver plane
Applications
SoundScoop provides:
● Air transfer (crossflow ventilation)
between internal spaces of buildings as
part of a natural ventilation system.
● Sound reduction between noisy areas and
quiet areas, for example between
circulation spaces and working, meeting
or teaching spaces.
● Speech privacy, allowing normal
undisturbed speech in adjacent areas.
Examples of use:
● Offices: between open plan offices and
meeting rooms, or between two meeting
rooms.
● Education buildings: between circulation
spaces and classrooms.
● Hotels: between bedrooms and corridors.
● Health buildings: between patient areas
and circulation areas.
Acoustic design
SoundScoop uses a highly innovative
approach to acoustic design which allows a
large unobstructed ventilation area. The
open design is based on selective sound
absorption at key frequencies, and does not
rely on baffles or diverters.
SoundScoop has been designed in
association with Arup in a collaborative
approach to acoustic design, natural
ventilation performance and product
development.
quiet boardroom
SoundScoop positioned
outside plane of source
and receiver
SoundScoop and natural ventilation
Natural ventilation is a key strategy in
providing a healthy environment in
buildings whilst avoiding excessive energy
use. Cross-ventilation or free air transfer
between internal spaces is an important
aspect of ventilating the whole building. But
at the same time most buildings require
acoustic separation between noisy areas and
noise-sensitive areas.
SoundScoop has been specifically designed
to meet these conflicting requirements with
a large free ventilation area, low airflow
resistance and high levels of noise reduction.
SoundScoop can be used to meet the
acoustic and ventilation requirements of:
Building Regulations Part F Means of
Ventilation, Part L Conservation of fuel and
power, and Part E Resistance to the passage
of sound.
BB93 Acoustic design of schools - a design
guide.
BS 8233: 1999 Sound insulation and noise
reduction for buildings. Code of practice
noisy atrium
separating construction
noise source
plane
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SOUNDSCOOP
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FEATURES
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AND
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BENEFITS
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specially designed cover
grilles maintain free
area and low air flow
resistance
Features
● Optimised acoustic design for the transfer
of air between noisy and noise sensitive
spaces.
● Extremely low airflow resistance due to
an entirely unimpeded acoustic path
(coefficient of discharge Cd value of 0.71).
● Provides up to a 90% increase in open area
compared to previous market leading
product.
● Cost competitive solution.
● Available in standard and high
performance acoustic foam versions, and a
range of sizes to suit the application.
● All the configurations have been
independently tested for acoustic
performance.
● Designed and manufactured to allow flat
packed national and international
transportation, with unit weights ranging
from 1.7 to 18.3kg.
● Manufactured and available in the UK
ready assembled for installation on site.
Patent pending
acoustic attenuation
foam (standard or high
specification recycled)
The Architect
● Compact product due to small cross
sectional area and length
● Flexible in application
● Shorter length compared to other
solutions
● Simple detailing, with less impact on
the building
● Specially designed cover grille available
to match transfer requirements
● Fully recycled options available
The Acoustician
● Wide range of product options with
independently accredited test results
● The noise reduction is targeted at mid
frequency noise, typically the most
disturbing
ribbed configuration provides
high acoustic absorption
SoundScoop offers major benefits to the building team...
The Contractor
● Simple installation saves time
● Competitive cost solution
● Lightweight construction
● Smaller and shorter air transfer
openings
The M&E Consultant
sleeve of 100%
recycled ABS
large unobstructed
ventilation area
allows high airflow
rates
● Negligible pressure drop through
large open area
● Can offset low pressure loss against
other components in the natural
ventilation system
● Allows natural ventilation to be a
viable strategy
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4
Sound reduction (dB)
50
45
40
35
30
25
20
15
10
5
0
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SOUNDSCOOP
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SOUNDSCOOP
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TECHNOLOGY
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Acoustic performance technology
The acoustic performance of the SoundScoop
has been developed through an engineered
approach where the exact nature of the
source noise and receiver sensitivity has
been considered. As such, the unit is
targeted in terms of the sound it attenuates.
This means it outperforms any other
equivalent product on the market in terms
of attenuation of speech and footfall – the
requirements of an internal acoustic
transfer.
The graph below shows the SoundScoop
acoustic air transfer unit compared to the
previous best performing solution on the
market. It compares the SoundScoop 45%
open design to a 30% open design foam lined
duct, which was the market leading product.
The resultant noise ingress is better than
half as loud (about10dB(A) reduction in the
500Hz to 2kHz frequency range) for the
SoundScoop, with a 50% more open design.
SoundScoop acoustic performance vs
previous market-leading lined duct product
(both at 1200mm in length)
SoundScoop (45% open)
better SoundScoop
performance over the
most significant
frequency range
125 250 500 1000 2000 4000
Sound frequency (Hz)
previous
market
leading foam
lined duct
(30% open)
SoundScoop results
inhalf the speech
noise level, whilst
providing50%
more flow area
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The performance of the SoundScoop has
been achieved through consideration of
three design features, each of which are
necessary for it to work most effectively.
These are summarised below.
1. By positioning the unit out of the plane of
source and receiver, sound is forced to take
an oblique path through the vent thereby
removing the need for bends or splitters.
See page 2 illustration for example.
2. Optimised cross-sectional dimensions are
used to target attenuation over the desired
range of frequencies. The SoundScoop is
sized so that the ‘cut-on’ frequencies, end
reflection and amount of attenuation is
optimised for the target 500Hz to 2kHz
speech range.
Example applications
The table below gives specific examples of
how SoundScoop can be used. The product
has been specifically designed to attenuate
the mid frequencies (500Hz – 2kHz) as
speech and circulation noise constitute the
main source in commercial and educational
buildings.
3. The patented internal lining which
features ribs at regular centres has been
shown to provide more than 10dB of sound
attenuation in a given octave band. This is
achieved by:
- Firstly, there is resistive interference where
sound is reflected and partly absorbed at
frequencies whose wavelengths relate to the
period of the ribs.
- Secondly, the discontinuities result in
non-plane wave motion below the cut-on
frequency. In other words, low frequency
sound that would travel unhindered in a
uniformly lined duct is disturbed by the ribs
and more readily attenuated.
- Thirdly, the ribs and strips of sound
absorbing material prevent wave motion
along the length of the unit, forcing local
reaction between the sound and foam lining.
This is known to maximise the attenuation
in lined ducts.
The applications are based on the large open
areas required in naturally ventilated
buildings. For example, the ventilation path
for the classroom has a typical free area of
0.4m 2 .
Noisy space Noise-sensitive space SoundScoop type Effect
Open plan office Meeting room 300mm long Vent attenuation provides adequate privacy to the open
620 x 320 Standard foam plan space and appropriate control of noise ingress to the
meeting room
Atrium/primary Classroom 600mm long Vent attenuation provides adequate control of noise
circulation 620 x 320 Standard foam ingress to the classroom
Meeting room Meeting room 1200mm long Vent attenuation provides good standards of privacy so
620 x 320 Standard foam OR that even raised voices are not intelligible
900mm long
620 x 320 High specification foam
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5

6
Pressure loss (Pa)
60%
50%
40%
30%
20%
10%
0%
1.4
1.2
1
0.8
0.6
0.4
0.2
0
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SOUNDSCOOP
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FLOW
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PERFORMANCE
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The bar chart below shows the increase in
the unimpeded air flow path for the
SoundScoop acoustic transfer unit.
Percentage free open area of acoustic transfer unit
Previous market leading
foam lined duct
320 x 320mm
SoundScoop
The graph below shows the SoundScoop
acoustic transfer pressure loss for varying
air velocities. Typical system velocities will
be around 0.6 m/s, which results in a
pressure loss for the SoundScoop of less
than 0.5 Pa.
620 x 320mm
SoundScoop
Pressure loss of the SoundScoop acoustic transfer technology,
excluding any aesthetic cover grilles
0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1
Air velocity (m/s)
SoundScoop technology
provides up to 90%
increase in open area,
resulting in greater
flow rates
SoundScoop technology
provides a typical
pressure loss of less
than 0.5Pa
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SOUNDSCOOP
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PRODUCT
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RANGE
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Below are the sixteen SoundScoop
combinations of two cross-sections, two
foam types and four lengths that are
available. All units have been acoustically
tested with detailed results for frequency
bands available on request.
Acoustic performance and weight
Average mid-frequency Acoustic performance Unit weight
Length Dn,e (dB) Dn,e,w (dB) (kg)
(mm) 500Hz - 2kHz
Acoustic foam Acoustic foam Acoustic foam
Standard High spec Standard High spec Standard High spec
300 34 33 31 32 1.7 3.0
600 49 44 36 39 3.3 5.9
320 x 320
900 54 52 39 41 4.9 8.8
Flow performance
Free area (m 2 ) Coefficient of discharge, Cd
SoundScoop Cover grille SoundScoop Cover grille (inflow) Cover grille (outflow)
320 x 320 0.04 0.05 0.71 0.60 0.68
620 x 320 0.1 0.1 0.71 0.60 0.68
320mm opening
1200 60 60 42 44 6.5 11.7
300 30 29 28 29 2.5 4.6
600 41 37 33 35 5.0 9.2
620 x 320 900 49 45 36 39 7.5 13.8
1200 54 51 39 42 10.0 18.3
Typical sections of a 620 x 320mm SoundScoop
620mm opening
Front view
Cover grille removed for clarity
Length
Section
600mm length shown
Ceiling level
Alternative ceiling level
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SOUNDSCOOP
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FURTHER
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INFORMATION
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Services
Passivent has its own in-house research
team dedicated to developing techniques and
products for natural ventilation, and is a
leading partner in some of the most
important research projects in this field
including NatVent, a consortium of
European organisations headed by BRE.
We offer a comprehensive design and
advisory service tailored to your specific
project, covering both natural ventilation
design and product selection. Advanced
software based on CIBSE AM10 is used to
calculate sizes of air inlets and outlets to
achieve optimum performance.
Names of approved installers can be provided
on request.
PASSIVENT LIMITED
North Frith Oasts, Ashes Lane, Hadlow, Kent TN11 9QU Tel: 01732 850770 Fax: 01732 850949
Email: projects@passivent.com Web: www.passivent.com
Passivent Limited maintains a policy of continuous development and reserves the
right to amend product specifications without notice.
A member of the Building Product Design Group
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Other products
Passivent market a range of other natural
ventilation and daylighting products
including:
● Aircool façade ventilators - systems for
windows, curtain walling and walls
● Airstract and Airscoop roof ventilation
terminals
● Acoustic passive ventilation
● Ventilation control systems
● Mixed mode cooling systems
● Combined rooflights/ventilators
● Sunscoop tubular rooflight systems
● Metro modular rooflights
● Natural and assisted domestic ventilation
systems
● Fresh wall ventilators
● Tricklevent window ventilators
● Solar shading
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Produced by Ted Hastings/Rackley Design