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    Mechanical insulation: it isn’t sexy, but it’ll save you money

    Nathan Johnson

    “Insulation is the Rodney Dangerfield of the construction industry—it receives very little respect and is taken for granted.”

    Former American National Insulation Association (NIA) President, Ron King opened with this line in an article he authored for a 2007 issue of the perennial American insulation magazine, Insulation Outlook. It’s titled Insulation: The Forgotten Energy Technology and starts by suggesting that the knowledge base of mechanical insulation systems at the engineering, architectural, and facility-owner levels over the last 15 to 20 years has, in most cases, eroded.

    Why? Well King reckons that a major reason is because insulation systems don’t have the moving parts, bells and whistles, or fancy gauges of other building products to engage keen interest. Or, to put it as bluntly as King did, because insulation “isn’t sexy”.

    So if insulation is the “forgotten technology” of the construction industry because it isn’t sexy, then mechanical insulation might just take the cake as the most forgotten (read: ugly) building technology known to man.

    Mechanical insulation is used on all types of mechanical systems and equipment throughout a building, including boilers, HVAC systems, piping and ducts. It is generally more prevalent in commercial and high-density residential buildings, and it is used to retard heat energy flow for energy conservation, control the temperature of process equipment, control surface temperatures to protect personnel, reduce emissions of greenhouse gases, prevent or reduce condensation on surfaces and provide fire protection.

    In his article, King states that there are many implications for those overlooking, undervaluing or not maintaining mechanical insulation in their buildings. The most relevant to those involved in a project’s construction and maintenance is that inadequate or incorrect mechanical insulation means missing out on a healthy amount of energy and cost savings and potential for massive maintenance bills.

    ENERGY CONSERVATION

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    Along with maximising profit, providing practical architecture, protecting the environment and creating a landmark building, reducing the energy consumption of a building is always high on the list of priorities for a developer. Insulation is one of the easiest and cheapest technologies that can aid a reduction in overall energy bills and is one that can provide a faster return on investment than a lot of the fancier building technologies (King says that many times the ROI occurs in less than a year). 

    Heating and cooling already accounts for up to 50 per cent of a commercial building’s energy use and that’s before you consider that an estimated 20 to 30 per cent of all installed mechanical insulation is either damaged or missing and that one of the biggest causes of energy loss in mechanical building systems is through faults in piping and ducting insulation.

    Section J5 ‘Energy Efficiency of Air-conditioning and Ventilation Systems’ of the National Construction Code (NCC) Volume One addresses the need for adequate and correct installed mechanical insulation in an energy efficient building.

    Specifically, J5.2b contains the requirements for the insulating of supply and return ductwork and fittings used in an air-conditioning system and J5.2c,  the insulating of piping, vessels, heat exchangers and tanks containing heating fluids or cooling fluids used in an airconditioning system.

    Both have Deemed-to-Satisfy Provisions that require that the insulation technology complies with AS4859.1 - Materials for the thermal insulation of buildings, and meet minimum material R-values, depending on the material that is being insulated and where it is located within the building.

    Both provisions also provide details on how to correctly install the insulation for specific areas and types of insulating material. For example when insulating the ductwork and fittings of an airconditioning system the provision says the insulation must be protected against the effects of weather and sunlight and be installed so that it abuts adjoining insulation to form a continuous barrier and maintains its position and thickness.

    THERMAL CONDUCTIVITY

    K-values are not explicitly mentioned in the NCC but it is the more frequently used measure of mechanical insulation thermal performance. It measures the thermal conductivity of a material which is its ability to reduce heat exchange between a surface and the environment, or between one surface and another surface. Thermal conductivity is the more frequently used measure for mechanical insulation however R-Values are also frequently used. Generally, the lower a material's thermal conductivity, the greater its ability to insulate for a given material thickness and set of conditions. When choosing an insulating product, particularly for spaces with tight clearance issues, consider its thermal conductivity in relation to its thickness.

    VAPOUR PERMEABILITY

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    Vapour permeability is one of the leading causes of condensation and corrosion which greatly affects thermal conductivity and acoustic insulation over time. In severe ambient conditions where high temperature and high relative humidity exist, vapour will permeate through insulation until it reaches dew point conditions and condense to form water that saturates insulation. Beyond that, it is also important to use insulation that will offset condensation from pipes and ducts in attic and crawl spaces where mould, mildew and odours are difficult to remove or repair. Some high-end insulation products come with inbuilt vapour barriers while others require impermanent coatings to achieve an acceptable level of permeability. Consider the initial cost of vapour coatings as well as their recoat and maintenance costs before specifying.


    The ANIA says ask these questions before specifying:

    1. What’s the process?
    2. What are the process temperatures?
    3. What's in the process and in the exterior environment?
    4. Is the piping located around people?
    5. Is fire an issue?

    SO WHAT’S TO LOSE?

    As conduits for heating or cooling to reach other areas of the building, if building elements such as boilers, HVAC systems, piping and ducts are not insulated, you’re essentially allowing energy to escape to areas of your building you never use.

    The ANIA completed a heat-loss analysis of the “typical” insulated piping systems in an oil refinery to illustrate the difference between the worst-case scenario (uninsulated piping), best-case scenario (all piping being insulated), and the case of reality (where 21 per cent of the pipe insulation was damaged or missing). The experiment showed that when 21 per cent of pipe insulation is missing or damaged, only 52 per cent of the potential heat-loss savings is obtained.

    King says this begs the question: “why does this condition exist when it could be corrected to provide a significant return on the capital employed or maintenance dollars spent at the refinery?”

    OTHER CONSIDERATIONS

    The extent of savings achieved using best practice thermal regulation is in direct relation to the quality and type of insulation used and for those looking to create the most energy efficient buildings, choosing a product with the lowest thermal conductivity and vapour permeability is of the highest priority.

    However, it shouldn’t be understated that the thermal conductivity performance of an insulation material is only as good as its applicability to the project at hand, and therefore specifiers should consider a range of other things that will affect the performance and costs associated with insulation projects.

    FIRE AND SMOKE STANDARDS

    All insulation products should display relative compliance with BCA and Australian Standards for Fire Resistance, Combustibility, Flashover Point and Smoke. They should also be able to demonstrate manufacturing compliance with relative testing authorities. Some products, particularly those manufactured overseas, will also display other standards compliance certificates and while some, like the FM Approval mark, are industry leading, others might not be up to Australia’s high compliance standards.

    EASE OF INSTALLATION

    Size, operability and adhesive performance play an important role in the ease of installation. Substandard products need to be used in thicker applications to get the same thermal conductivity performance as high-end products which mean they can be more difficult to install, especially in spaces with tight clearance.  A smooth surface that allows for adhesion to a wide range of surfaces also saves installers time, and money, and where needed, specifiers should look for manufacturers that offer optional repositionable tissue acrylic adhesives on their products. Unlike conventional direct coated adhesives, products with adhesive backing provide 100 per cent coverage on the duct surface and on the foam insulation, ensuring no seepage or thermal bridging.  This feature also provides the additional benefit of repositionability, an essential requirement during installation. The insulation can be lifted off the duct numerous times during alignment without tearing the insulation.

    CALL BACKS

    A poorly adhered or poorly performing product will result in callbacks that result in loss of money for installers.

    APPEARANCE AND DURABILITY

    In some instances the insulation product needs to remain aesthetically pleasing throughout its whole lifecycle remains unchanged for the life of the building without sagging or giving a quilted look.

    SUSTAINABILITY

    Insulation’s contribution to a sustainable built environment goes beyond its role in reducing energy used to regulate the temperature interior spaces of a building. A product’s material makeup and the methods used to manufacturer it are arguably more important because its often the case that a product specified to lessen the environmental impact of one building is actually doing more damage to the environment during its material sourcing, manufacturing and transportation stages. Buyers and specifiers should look for products that have been accredited by leading green building councils and product assessors such as LEED, Estidama and Australia’s Green Star.

    THIRD PARTY CERTIFICATION

    Code Mark is a third-party certification scheme for building products and systems, developed and managed by the Australian Building Codes Board (ABCB). Code Mark certification provides reliable evidence of a building product or system complying with the National Construction Code (NCC).

    The process to obtain a Code Mark Certificate of Conformance involves not only demonstrating that a product is in full compliance with the NCC, but demonstrating it is installed in accordance with the manufacturer’s instructions, without compromising its performance (i.e. the installed product is in compliance with the NCC). As such, Code Mark is more of a ‘building system’ certification scheme.

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