Iano's backfill

Green Giant

Architecture firm SOM's very green Pearl River Tower, planned for Guangzhou, China, is described in both Super Tall and Green  (Metropolis, August 2006) and SOM's skyscraper innovation has moved to China (Architect Record, 07.06).  Included among its sustainable features are:

• An underfloor radiant cooling system that passively circulates air within the building's interior
• A sculpted building form that channels wind into turbine-driven electrical generators located on two of the building's mechanical floors
• A double-wall curtainwall system that preconditions fresh outside air and directs exhaust air to mechanical floors where excess heat is captured and reused
• Fuel cells located on-site that produce electricity more efficiently than that available from the public grid; Waste heat from the fuel cells is also recycled into the building's heating and cooling systems.
• A condensate reclamation system to reduce HVAC system water consumption

The 1000-ft tall building is scheduled for completion in Fall 2009. According to Metropolis Magazine, the building is designed to be the world's first "zero-energy supertall building in the world," though this claim is not fully explained.

Developments in Glass Technology

Building Design & Construction, 03-04, includes a number of articles on new developments in glass technology.

Testing curtainwall glazing in situ
Keeping Glazed Walls Healthy discusses techniques for in-place verification of the condition of curtainwall glazing units. The article notes that glass units frequently do not last the life of other major curtainwall components, and their evaluation can be important as the building ages, or as part of due-diligance evaluation during building sales.

Test ASTM E576 "Standard Test Method for Frost Point of Sealed Insulating Glass Units in Vertical Position" specifies a method for determining the moisture content of air within sealed glass units and can be used to predict future fogging of units due to internal moisture condensation.

A second ASTM test, identified in the article as E1392, is described as a relatively new and not well known test for non-destructive testing of structural-glazed installations. In these installations glazing is attached to the curtainwall system only with silicone adhesive and without any mechanical attachment. It appears to this author that the ASTM reference provided in the article is incorrect--and should be ASTM C1394 "Standard Guide for In-Situ Structural Silicone Glazing Evaluation".

On a separate topic, the article also discusses the occasional spontaneous breakage of fully tempered glass due to the unpredictable pressence of nickle sulfide inclusions in these glass products. To avoid risks to occupants, some glass manufacturers recommend against the use of fully tempered glass in vertical curtainwall glazing or in other locations where falling glass could pose a threat to building occupants or passers-by.

New Low-E High-Transparency Coating
Pyrolytic glass coating debuts discusses Pilkington's new Eclipse Advantage coating that provides higher transparency and lower reflectivance than Pilkington's current Eclipse product that it replaces. The low-e coating is also noteworthy for being applied in a pyrolytic "hard coat" process that is more durable than competing sputter applied "soft coat" products. The hard coat product is claimed to be less subject to damage during secondary operations such as laminating, cutting, heat treatment, etc.

Product Updates
Products Glass provides several pages of annoucments on glass products related to sound control, fire control, low-e glass, high-efficiency clear glass, protective glass films, safety glass, wire glass, and more.

What Really Happened To The John Hancock Tower

With the expiration of a 17-year gag order on the legal settlement surrounding the massive curtainwall failure of Boston's John Hancock Tower, forensic engineers Simpson Gumpertz & Heger can finally tell what was the source of failure that led to the replacement of over 10,000 sheets of glass.

The New Seattle Library

Seattle's Eccentric Book Behemoth (ENR November 3, 2001 cover story) discusses the unique structural system employed in Seattle's new library building, and the challenges entailed in erecting this "eccentric" building. The combination of high profile architecture by designer Rem Koolhaas and unusual construction requirements make this article good reading for students interested in the intersection of design and construction.

Some interesting aspects of this project include:

• The extensive use of skewed and sloping columns to minimize the number of columns and eliminate the need for transfer beams
• A hybrid structural steel/aluminum curtainwall skin that provides the building's seismic lateral bracing
• Multistory structural boxes cantilevered with full height perimeter steel belt trusses
• The use of computational fluid dynamics modeling to size the building's smoke evacuation system
• A unique strategy for unloading steel falsework in a controlled sequence

This article is well-illustrated and also includes an interesting discussion of the problems encountered in coordinating the curtainwall design with final design and fabrication of the steel grid behind it during the construction phase. An unusual set of dependencies between the work of the curtainwall and steel fabricators appear to have been a significant factor in the building finishing behind schedule. In related editorial, A Tight Budget Does Not Mean Cutting Creativity, ENR also reports that the building was constructed for $275 per square foot (including parking), a figure reportedly in line with other comparable city library buildings.

21 - Cladding With Metal and Glass Links

This article contains external links to resources on the Web relevant to Chapter 21 Cladding With Metal and Glass.

Alcoa Cladding Systems

Aluminum panel cladding systems

Archiglaze International

Structural Glass Systems

Copper Development Association

Copper in architecture resource site

Pilkington Planar Curtainwall

Specialized fittings for structural glass curtainwall systems

RHEINZINK

Downloadable architectural and technical information