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Dan Bettenhausen
Abstract:
Double Skin Facades (DSF), constructed from individual aluminum framed curtain wall assemblies, provide a means of achieving acoustic and thermal performance that exceeds what can be produced by single leaf systems. To harness these benefits additional considerations are required throughout the processes of design, fabrication, site logistics, installation, and envelope commissioning. An extensive conceptual discussion of these topics is provided. Furthermore, two example problems are investigated. In the first example problem, the results of a computational fluid dynamics (CFD) model in two configurations are compared with a model of effective thermal conductivity derived from the experimental work of El Sherbiny (1982). In the first configuration the CFD model incudes turbulence modeling by the two-equation method of Mentor (1994) and in the second, no turbulence was modeled. It was found that the results of both cases compared favorably when values of the effective conductivity predicted were compared to the experimental work; however, significant variations in temperature determined by the CFD analysis cannot be replicated by applying the effective conductivity determined to a model of diffusive heat transfer. The implications of this outcome for cavity wall design are discussed. In the second example problem WINDOW FEA software is used to analyze temperature distributions in sealed double facade cavities with and without blinds. It is shown that the placement of insulated glass in either the inner or outer leaf, and shade deployment, significantly affect cavity temperatures which range from 101 F to 176 F.
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Angel Ayón • Laura Boynton
Abstract:
Originally known as The Master Building, 310 Riverside Drive in Manhattan's Upper West Side is a 28-story tower completed in 1929 as an apartment hotel and museum. With its Art Deco design rendered primarily in brick masonry and monumental steel windows above the ground floor entrances and marquees, this designated-Landmark is a unique example of the high-rise typology that came to define the NYC skyline during the first half of the 20th century.
It is a familiar question to preservationists – how do you balance the historical value of character-defining existing single-glaze windows with their historically poor energy performance? This presentation examines the steel window and storefront restoration, rehabilitation and replacement options devised for this project. It outlines the decision-making process that led to the retention of the original non-thermally broken steel window frames and the installation of replacement vacuum insulated glazing (VIG) within them, and the process of pursing custom-made VIG panels to replicate the textured blue glass at the side lites.
VIG is not a new glazing technology, but until very recently it required importing from Asia or Europe at a premium in cost and long lead times. Few projects in the US have been fully realized using VIG, and data on its performance in existing frames is practically non-existent. Now that VIG is becoming more readably available in the US, the technology seems poised to bridge the long-standing gap between preservation and the kind of high energy performance usually reserved for new buildings.
For this case study, samples of VIG were installed in existing frames prior to the work implementation to monitor heat flow through the proposed replacement VIG in comparison with the original single-pane glass and existing non thermally-broken steel frames. Data collected from this case study indicated that the VIG panes decrease the U-value of the system by about 73% (almost 4 times improvement). The presentation will present a critical look at VIG and its application to existing buildings as a viable alternative to wholesale window replacement.
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Sophie Pennetier • Houston Drum
This article documents the development or the design of two skylights on the Sacramento Capitol Annex Project throughout Design Assist and sheds light on the essential collaboration between Architects and Facades Contractors to generate filigrane glass skylights solutions which would not have been made possible under a linear Design Bid Build delivery process.
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