The Relationship Between Flexible Duct Insulations and Green Building

You would think that potential energy savers like fibreglass duct liner or foil faced duct wrap insulations would be high on the list of contributors to Green Building technology. Surprisingly, this is not the case.

For the past few years there has been a change on the construction scene towards more sustainable and environmentally friendly building practices. We are hearing more and more about Green Building and LEED¨, but what exactly are these groups and ideas, and how do they pertain to mechanical insulation and more specifically, standard sheet metal insulations?

Simply put, LEED (Leadership in Energy and Environmental Design) is a master report card that encourages and accelerates global adoption of sustainable Green Building and development practices through the creation and implementation of universally understood and accepted standards, tools and performance criteria. The Canadian Green Building Council (CaGBC) is the Canadian standards committee in charge of establishing the LEED criteria by evaluating projects, forming qualified specialists and promoting Green Building in Canada.

LEED Canada has assigned a project checklist with various potential points assigned to sub-groups related to the specific project. These are further broken down to more specific levels:

There seems to be a great deal of confusion around several aspects of the potential points system as it might relate to mechanical insulation. LEED certification applies only to building projects, not materials, products or services. Obviously, the first two categories (1, 2) have no bearing on the subject in question and surprisingly, insulation is a very small contributor for total points in the other four groups. Duct insulation may help contribute minimally to the other categories.

Insulation must be tested per ASTM C518 for R-value (3) as a prerequisite, but only needs to reduce energy costs to ASHRAE 90.1 specified levels. All mechanical fibreglass insulations will meet or exceed this requirement, but the only opportunity for credit points would be with lesser quality (recyclable) building insulation in other aspects of the project. Both recycled materials and regional content (4) exclude mechanical systems, (which includes insulation) from the LEED point criteria. (At any rate, the high sensitivity of most flexible mechanical insulations would not allow the use of recycled content in the final product; also, most North American manufacturing plants are huge complexes with high volumes and are all located in the highly populated eastern side of the continent). This discounts any regional points for proximity to manufacturing location.

CaGBC does not specify any specific levels of emissions (5) for materials other than Volatile Organic Compounds (VOC levels) in paint and sealants, composite woods, carpet and coatings. There are no specific emission level requirements for insulation other than as a contribution to the overall building VOC levels. About the only area for additional LEED points is in the innovation area (6) of acoustic comfort where it is possible to significantly contribute to the reduction of noise level of a system with the use of fibreglass duct liners.

LEED is a work in progress. Obviously, this column has only scratched the surface. For more in-depth coverage you can Google the subject and find such sites as for a volume of discussion topics related to Green Building.

Garth Liseth has been actively involved in the mechanical insulation field since 1973 and is a past resident of the Thermal Insulation Association of Canada. Garth is employed by Crossroads C & I Distributors Inc. in its Burnaby, BC office.