Morrison Hershfield will be presenting two sessions at this year’s Facade Tectonics World Congress Conference in Los Angeles.
Stéphane Hoffman, Senior Building Science Specialist and Facade Engineering Practice Lead, will be presenting Energy Code Implications for Spandrel Design during Session 1 at 8:30 am on Monday, October 10th.
Recent energy codes have raised the bar in terms of performance expectations for the building envelope. These new codes can challenge the performance of traditional unitized glazing systems. Especially challenging is the opaque wall U-values based on the assumption of continuous insulation for metal framed assemblies. The implication of glazing ratios on glazing system U-values and in particular recent findings of spandrel performance will be summarized. A comparison of traditional parallel path (or area weighted approach) analysis and new approach to considering the effect of lateral path using 3D thermal modeling will be highlighted. The results of comparison of these two approaches in relation to guarded hotbox testing will be presented. Examples from the ASHRAE 1365-RP research report on the impact of 3D thermal bridging and the BC Hydro Envelope Thermal Bridging Guide will be used to illustrate the impact for traditional spandrel design when the effects on interface details are accounted for. Looking beyond “code compliance” examples using the latest 3D thermal modeling and innovative materials will demonstrate how the effect of thermal bridging can be mitigated. Proposed methodology to specifying spandrel performance in light of the shortcomings of current modeling techniques will be outlined.
George Torok, Building Science Specialist, will be presenting Canadian Window Wall: Design Challenges and Opportunities during Session 1 at 8:30 am on Tuesday, October 11th.
One of the defining characteristics of new high-rise residential apartment building design in Canada today is the thermally broken, open-back aluminum frame ‘window wall’ building envelope system. Until recently, Canadian building codes and Canadian and North American fenestration standards have not recognized window wall as a distinct cladding system. Canadian window wall systems have evolved on a largely trial and error basis. This changed earlier this year with the release of the most recent edition of the model National Building Code of Canada that includes, for the first time, a category of ‘other fenestration assemblies’ to address window wall and other glazing systems, setting out required and recommended performance and testing requirements. Work is also in progress on an installation standard under the aegis of the Canadian Standards Association. While performance requirements are being sorted out at home, Canadian window wall manufacturers are promoting their systems in the United States (USA) to compete with similar systems in that market. However, there are significant technical and aesthetic differences between Canadian and USA window wall systems that should be taken into consideration by architects, builders and developers.
George’s presentation will provide a brief overview of the development of Canadian Window Wall, design in the context of upcoming requirements, assembly and installation details that could affect design, construction and performance of the building envelope when used for high-rise residential construction in the US.