Growing industry awareness of the importance of energy efficiency and sustainability has highlighted the need to optimise the efficiency of HVAC plant and air distribution systems and minimise unnecessary thermal loads and prevent the damaging effects of unwanted moisture. According to the Department of Environment and Energy, non-residential HVAC systems in Australia consume an estimated 9 per cent of electricity produced in Australia, so the importance of these tasks cannot be underestimated.  

Air handling units (AHUs) and air distribution systems “condition and distribute air throughout a building in order to maintain satisfactory indoor air quality (IAQ) and comfort conditions (including temperature and humidity)”. The HVAC Air Handling Units Factsheet emphasises that the appropriate installation of AHUs and Air Distribution Systems is essential to minimise air leakage and pressure drops. Common causes of such leaks and pressure drops are poor ductwork layout, inappropriate use of flexible ducts, and inadequate sealing at joints and access points.

Appropriate and effective insulation methods are also very critical elements of air distribution systems. Insulation is typically applied to the external surface of ductwork to minimise the risk of condensation and to reduce thermal energy gains or losses, assuring system efficiency.  Typically, internal ductwork linings are used to reduce noise within a duct due to fan noise or air-flow friction. However, innovation in duct manufacturing is increasing opportunities to internally insulate the entire duct. 

Increasing health and sustainability awareness and energy efficiency demands are revealing a variety of potential problems associated with the insulation of air distribution ducting. One such problem is where thermal specifications require insulation that is physically too large for the space available on site.

The intrinsic shortcomings of traditional insulation products risk thwarting desired outcomes. Fibrous insulation issues include: risk of moisture ingress, inconsistent thermal insulation performance (R-value) due to compaction, risk of exposed fibres, and potential poor appearance of lagging due to ease of damage.  Flexible ducting issues include: airflow pressure drops and inconsistent R-values due to compaction.  Pre-insulated duct solutions have problems with poor noise attenuation characteristics and ease of damage.

Sekisui Foam Australia now offers an extended range of innovative Thermobreak® products that provide new solutions to building owners, consultants, contractors, and manufacturers and address health and safety concerns as well as maintaining long-term thermal performance. Thermobreak® Insulation has been extensively used by the HVAC industry for many years in sheet and roll form and its unique properties permit smart new innovations that include:

Thermobreak® Ductwrap

Thermobreak® Ductwrap is supplied pre-fabricated to enable very quick, easy, and reliable application of external ductwrap insulation by the steel duct manufacturer, mechanical contractor or duct lagger.  


Benefits offered by Thermobreak® Ductwrap include:  

  • Closed cell insulation removes risk of condensation and ensures durable performance
  • Fibre-free insulation provides a clean and tidy solution that addresses installation and safety concerns
  • Pre-cut V grooved wrap, which is quick and easy to apply in sheet metal shops or on site
  • A pre-grooved Flange Cover that is easy to apply on site
  • Installed appearance is clean, durable, and robust
  • Thermobreak® No Clad option for situations where the duct is exposed to weather

Thermobreak® Acoustiplus

Thermobreak® Acoustiplus is an innovative new generation, physically cross-linked polyolefin foam duct liner that provides an acoustic solution for steel duct and pre-insulated rigid duct. Thermobreak Acoustiplus is supplied with reinforced aluminium foil facing and is available with a pressure sensitive adhesive backing.



Benefits offered by Thermobreak® Acoustiplus include:  

  • A fibre free insulation provides a clean and tidy solution that addresses installation and safety concerns and is inherently mould resistant
  • Excellent sound absorption at low thicknesses
  • Extremely lightweight 25 kg/m3 foam density
  • Excellent thermal performance 0.035 W/mK @ 23oC
  • Very low water absorption
  • Fully tested and compliant with relevant sections of AS4254 and UL181
  • Extremely easy to fabricate (die-cutting, installing)

Thermobreak® Acoustibox

A new generation of physically cross-linked polyolefin foam based Thermal Acoustic Cushion Head and Plenum Boxes, Thermobreak® Acoustibox is manufactured using a unique proprietary composite foam. It is strong and stiff, eliminating the use of heavy steel, and provides excellent thermal and acoustic properties allowing a single material to be used.


Benefits offered by Thermobreak® Acoustibox include:  

  • As there is no metal, it is lightweight, eliminating the need for rafter rod supports
  • Manufactured at various thicknesses to comply with NCC R-values
  • Robust and strong, allowing for ease of installation with minimal risk of damage
  • Can be manufactured to fit the neck of all common registers/diffusers
  • Can be supplied pre-assembled or flat packed in a two component pack for reduced transport costs
  • Fibre free insulation provides a clean and tidy solution that addresses installation and safety concerns and is inherently mould resistant
  • Installed appearance is clean, durable, and robust

Thermobreak® Quadro™ RD 

A lightweight pre-insulated round duct enabling quick, easy, and reliable installation. The unique Thermobreak® Quadro™ RD duct structure ensures a strong, low sag, negligible air leakage, but highly versatile duct for small and medium size residential building applications.


Benefits offered by Thermobreak® Quadro™ RD include:  

  • Fully tested and compliant with relevant sections of AS4254 -2002 Ductwork for Air-handling systems in buildings and UL 181 Factory-made Air Ducts and Connectors
  • Easy to assemble in ceilings and tight spaces due to its lightness, flexibility, and ease of handling
  • Elbows and T joints can be easily fabricated on site to fit
  • Manufactured to various thicknesses for compliance with NCC R values
  • Robust and strong allowing easy installation with minimal risk of damage
  • Conformable for tight clearances

CodeMark Certified 

Sekisui Foam Australia is committed to third party certification with Thermobreak® insulation and Thermobreak® Tube insulation products being CodeMark certified for many years. A CodeMark Certificate of Conformance provides confidence to architects, consultants, builders and regulatory authorities to specify, use and approve Thermobreak® products due to the rigorous procedures required to obtain CodeMark certification, and the credibility of the certification process.

CodeMark certification is one of the most respected means of demonstrating compliance with Specification A2.2 ‘Evidence of Suitability’ of the NCC.  It is more reliable than test report evidence, because it ensures that the product tested is representative of the product being supplied to the marketplace.

CodeMark certification is also more reliable than product-only certification schemes.  For example the NCC BCA may require a product to meet several performance criteria for compliance.  This is accounted for during the CodeMark certification process.  Furthermore the CodeMark certification process includes an assessment of how a product is installed, whereas product-only certification schemes do not. Incorrect or faulty installation of a product may reduce its performance and render it non-compliant. 


The Thermobreak® range offers new and innovative solutions to meet the needs and concerns of anyone involved in the HVAC industry, providing the most advanced product while achieving cost savings in both installation and long-term energy efficiency. It is suitable for thermal and acoustic insulation of mechanical services, refrigeration, and building elements.

Thermobreak® are high performance, low risk, Australian manufactured products that provide durable insulation solutions.

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