Case study - Sound Absorbing Walls for Rooftop HVAC

Case study

Application: Sound Absorbing Walls for Rooftop HVAC
Wall Product: AcoustiSorb
Manufacturer: ModularWalls
Product: Martini Absorb
Performance: Sound Absorption
Martini Absorb

Acoustic Insulation for Sound Absorbing Walls

Application Overview

Commercial HVAC units are often located on rooftops to save space and provide easy access for maintenance. Rooftop HVAC units can create an acoustic design challenge for architects, especially when the HVAC units can be seen and heard from neighbouring multi-storey apartments.

Rooftop HVAC units typically incorporate a series of motors, fans and chillers that produce a range of noises such as throbs, rumbles, whistles, whirrs and hisses. If these noises aren’t acoustically treated they can have an adverse impact on the surrounding environment and affect the health and wellbeing of neighbouring residences.

ModularWalls manufacture an aesthetic noise attenuation barrier called AcoustiSorb. AcoustiSorb is a pre-finished aluminium modular wall panel system that’s commonly used to enclose rooftop HVAC units.

The panels are slotted into place between supporting posts with their perforated surfaces faced inwards towards the noise source. Martini Absorb is at the core of the panels, and because of its HD, XHD, XXHD density variations, the panels can be tuned to meet specific absorption requirements across a range of frequencies.

Application images Click here to view application images Application images Application images Manufacturing images Manufacturing images Manufacturing images Manufacturing images


Martini Absorb is manufactured from thermally bonded polyester fibre with up to 80% recycled content from post‐consumer PET packaging such as empty drink bottles. Features such as high performance acoustic absorption, lightweight and low bulk properties, and weather resistance makes Martini Absorb the ideal acoustic insulation core for AcoustiSorb wall panels.

The AcoustiSorb panels are fabricated from two pre-finished aluminium skins which are shaped and cut to the required length. Corresponding lengths of Martini Absorb are then inserted and sealed between the skins.

Martini Absorb

The AcoustiSorb perforated skins are shaped and cut

Martini Absorb

Typical applications

AcoustiSorb wall panels with a Martini Absorb core are suitable for external and internal noise attenuation applications. The wall panels provide highly effective sound abatement in noise-intensive environments such as transport corridors and businesses that make extensive use of noisy machinery.

Typical applications include the following:

  • Rooftop HVAC units
  • Railway corridors
  • Loading docks
  • Machine rooms
  • Perimeter acoustic barrier walls

Technical Project Support

The DesignSmart team has a wealth of construction experience and utilise industry-leading building science research for acoustic, thermal and fire insulation products. As the experts in building insulation they can assist with:

  • project-specific support
  • value engineering challenges
  • specification documentation
  • system design detailing
  • product installation and certification

Call the DesignSmart team on  1800 354 044 or visit our Technical Project Support page.

Publication: 26/09/2017
Information is based on the version of the National Construction Code (NCC) which was current at the time of publication. There may be changes in subsequent versions of the code which mean parts of this case study no longer apply.

Whilst every precaution has been taken to ensure that the content in this case study is both current and accurate at time of publication, CSR is not responsible or liable for any errors, omissions or for any consequences arising from the use of this case study. The information in the case study is general in nature and has solely been prepared for marketing purposes and should not be interpreted as specific advice for a project or product application. In all cases, the reader should seek professional, project specific advice prior to making design or product decisions.

Contact DesignSmart

For architects, engineers and builders:

  • Expert insulation advice
  • Project and value engineering support
  • Industry-leading building science research
1800 354 044
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Learn how Martini Absorb is used in outdoor sound absorbing walls. Download the PDF for more information.

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