Vented Facades

Window Facade

The simplest method of enhancing the acoustics of a vented facade is to place the NAT Vent Attenuator behind an openable window. In this instance, the window is used to control the air flow into the building, maintaining the thermal performance of the facade as well as keeping the weather out.

Vertical Louvre

A vertical louvre is ideal on windowless facades or where window space is at a premium.The facade can either feature a standard weather lourve or a bespoke solution can be designed into the facade face.

Horizontal Louvre

Rather than mount the vent along the vertical plane of a facade, a horizontal installation is ideal below a window sill.

Discrete Facade

As forward thinking acoustic consultants, we have done many alternative and discrete facade installations. The NVA’s unique flexibility means that it can be installed under bench seating, in flower boxes, play boxes or small steps within the facade.

Facade Inspiration

Scroll though images of example facade installations, where MACH Acoustics have incorporated the NVA.

Acoustic Performance

MACH Acoustics produce calculations based on procedures described in BS EN 10140-1:2010, BS EN 10140-2:2010 and BS EN 10140-5:2010. The NVA is tested using our in house testing rig calibrated to BS 7251.

Air Flow Performance

The NVA offers extremely low resistance to air flow as it has been designed specifically for low energy buildings.

Flight Path Demo

Naturally Ventilating with Aircraft Noise using the NAT Vent Attenuator

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The MACH Products NAT Vent Attenuator was used to successfully naturally ventilate Windford Primary School; a school under the flight path of Bristol International Airport. This video shows the aircraft noise is barely audiuable inside the school, even with vents open.

Simple Installation

Installation to a duct typically takes less than 1 hour. The acoustic foam block are simply stacked to create the honeycomb formation in the duct, orientated for air flow through the gaps. Since it isn’t a pre-defined size, there isn’t a tight specification to follow or critical dimensions to build to, it is bespoke without the cost.

Co-ordination

The lightweight and flexible nature allows the product to be installed in a number of unique ways. This can be essential when a large unforeseen obstacle requires to be navigated meaning that traditional metal cased units cannot be manipulated.

MF Track Installation

NAT Vent Attenuator MF Track Installation

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A simple Revit render, to illustrate installation within MF Tracking.

Vented Facade Installation

NAT Vent Attenuator Vented Facade Installation

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A simple video showing the ease of installing the NVA into a vented facade.

Focus on Vented Facades >

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Core Applications > Window Facade

Window Vent

The simplest method of enhancing the acoustics of a vented facade is to place the NVA behind an open-able window. In this instance, the vwindow is used to control the air flow into the building, maintaining the thermal performance of the facade as well as keeping the weather out.

Bulkhead

A small bulkhead is typically mounted behind the facade opening. The NVA may simply be supported by MF tracks or may be enclosed by purpose built ducting (plasterboard, timber etc.). The flexibility of the NVA means that actuators to operate the vent/window can easily be accommodated for, including service hatches. The window vent can be at low level, high level or incorporated into curtain walling.

Installation

Quick, simple and adaptable Installation is one of the key benefits of the NVA. The process is broadly the same for most applications. The tessellating foam is arranged into honeycomb pairs by alternating orientation, then simply slid into the duct. Since the foam is malleable and can be cut, fitting around building services or any on-site alternations can be easily achieved. Installation generally takes under one hour - saving money and construction time.

Case Study

London and West London Academies, two large £30M+ Academy are both designed around a natural ventilation, incorporating cross ventilation. Both schools were required to meet BB93 and BB101 ‘Ventilation of School Buildings’. MACH Acoustics worked with Fosters and Partners to develop a practical solution. Our findings were that the cost of conventional attenuators along with their size and short falls in performance prohibited the use of these devices but allowed for the NVA.

 

The academies featured many different imaginative implementations of the NVA as a cross ventilator, all venting into a central atrium. Air passed though the facade via actuated windows through bulkheads at ceiling height containing the NVA.

 

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Core Applications > Vertical Louvre

Design

A vertical louvre is ideal on windowless facades or where window space is at a premium.The facade can either feature a standard weather lourve or a bespoke solution can be designed into the facade face. The vent can be actuated or using a vertical vent, a simple door can be used to control the internal flow of air.

Install

Quick, simple and adaptable Installation is one of the key benefits of the NVA. The process is broadly the same for most applications. The tessellating foam is arranged into honeycomb pairs by alternating orientation, then simply slid into the duct. Since the foam is malleable and can be cut, fitting around building services or any on-site alternations can be easily achieved. Installation generally takes under one hour - saving money and construction time.

Case Study

Winford school is located directly under the flight path of Bristol Airport, as such noise ingress is a significant issue. During the design stage of this building several design options where reviewed. The school is a prime example of the versatility of the NVA and MACH Acoustics. Facade ventilation is incorporated through window and horizontal louvres. Cross ventilation is applied through internal benches and exhausted through atrium vents. The horizontal louvres feature a 90deg bend to increase the attenuation of the vent and visual impact.

 

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Core Applications > Horizontal Louvre

Design

A horizontal facade installation is commonly mounted below a window sill. The vent can also be mounted at ground height with an external extruded bulkhead containing the NVA, saving internal space and creating a box that can be used for landscaping features - see case study below. 

Install

Quick, simple and adaptable Installation is one of the key benefits of the NVA. The process is broadly the same for most applications. The tessellating foam is arranged into honeycomb pairs by alternating orientation, then simply slid into the duct. Since the foam is malleable and can be cut, fitting around building services or any on-site alternations can be easily achieved. Installation generally takes under one hour - saving money and construction time.

Case Study

Dartington Primary School is located in close proximity to the A384; a large busy road. A number of natural ventilation strategies were developed in cooperation with Arup, including the use of landscaping as a barrier.
This inspiring solid timber project presented challenges internally and externally. Natural ventilation is achieved through an external horizontal bulkhead cross-venting through the roof.

 

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Core Applications > Discrete Facade

Design

As forward thinking acoustic consultants, we have done many alternative and discrete facade installations. The NVA’s unique flexibility means that it can be installed under bench seating, in flower boxes, play boxes or small steps within the facade.

Install

Quick, simple and adaptable Installation is one of the key benefits of the NVA. The process is broadly the same for most applications. The tessellating foam is arranged into honeycomb pairs by alternating orientation, then simply slid into the duct. Since the foam is malleable and can be cut, fitting around building services or any on-site alternations can be easily achieved. Installation generally takes under one hour - saving money and construction time.

 

The bench was constructed with a hollow void to hold the NVA. Following the insertion of the NVA, the final slats were installed across the bench and grill on the inside.

Case Study

St Peters school is located in relatively close proximity to the M5 and as such, environmental noise levels are too high to allow for natural ventilation through openable windows. MACH Acoustics was employed by South Gloucestershire Council to provide a range of design options to prevent noise ingress into this classroom. A unique discrete facade vent, contained within a bench seat was employed.

Download the Case Study

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Core Applications > Facade Inspiration

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Performance > Acoustic Performance

Dnew vs Free Area % vs Depth

The NVA frequently performs better on-site. Attenuators are usually tested in accordance to BS EN ISO 10140-1:2010; however this is limited to attenuators with an opening of less than 1m2. Typically on site an attenuator has an opening in the order of 1.2m2, though this can vary in size for different applications.

Case Study

The outstanding performance of the NVA allowed for multiple facade ventilation features at Winford Primary School - located directly below Bristol Airport flight path.

 

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Performance > Air Flow Performance

CFD Modelling

Low face velocities (<1m/s) associated with natural ventilation makes accurate measurement of pressure drop difficult and prone to errors. For this reason, MACH Products used CFD to model the pressure drop of the NVA.

25% 1ms
25% 5ms
50% 1ms
50% 5ms
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Performance > Flight Path Demo

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Installation, Co-ordination and Cost Savings > Simple Installation

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Installation, Co-ordination and Cost Savings > Co-ordination

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Installation, Co-ordination and Cost Savings > MF Track Installation

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Installation, Co-ordination and Cost Savings > Vented Facade Installation

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