Friday, April 4, 2014

Sun/Shade & Urban Development – March 2014

The following relate to urban development and urban design in general, specific projects, and sun/shade issues. They were derived from our twitter feed @SunPosition

Shadow Conditions That Increase the Amount of Thermal Stress on Glass | AAMA   

Thermal Stress Building Example
















SCHAUMBURG, IL - In the June 2013 publication of Glass Canada, Margaret Webb, Executive Director of the Insulating Glass Manufacturers Alliance (IGMA), gave an overview of a technical services bulletin developed by IGMA to assist the industry in providing a proper technical understanding for thermal stress. The bulletin, TB 1300-13, is titled “Guidelines for Thermal Stress Considerations.”…

One of the most common examples of thermal stress breakage can occur from conditions arising from a clear cold winter night when the glass cools to an ambient condition over night and then in the morning or when the glass is exposed to solar exposure with shading conditions that allow portions of the glass to stay cold while other portions of the glass are being heated by the solar exposure. The heated areas of the glass tend to expand being forced into a state of compression, while the cool zones that are encapsulated by the framing system and/or shaded area are forced into a state of tension…

Experience and examination of fracture origins has verified that the conditions described can and will occur from thermally induced glass fracture and can occur in summer or winter conditions. This is because the thermal gradient between the heated area of the glass and cooler edges is the critical condition to evaluate.

The shadowing of the glass enhances the thermal stress issue and certain types of shadows have more of an impact than others. The shadows that cast an angular shadow or a “V” shape on the glass have been demonstrated to develop larger thermal stresses that linear shadows…

These guidelines were developed from the collective experiences of insulating glass manufacturers, glass and glazing material suppliers, contract glaziers, design engineers, industry consultants and persons experienced in successful IG manufacturing. The document reflects existing technology and will be subject to periodic review and change when new technologies become available as is the normal process in IGMA.

TB 1300-13 contains various sections to cover the importance of thermal stress conditions. The shadow portion is just one of the many issues that interest the architect, designer, glass fabricator, glazing contractor and others relative to the subject…

more - http://t.co/NVNl29GF9J

Here's the 50-Story Condo Skyscraper Headed to Eighth & Olive | via @CurbedLA

 

LOS ANGELES, CA - This 50-story mixed-use tower by recently-prolific Downtown developers Onni Group may not be architecturally exciting—it looks a lot like a giant plastic cigarette lighter posted up at the corner of Eighth and Olive—but next to what will be Onni Group's 32-story tower, it at least makes a good pairing. (Onni's other tower can be seen in some of the renderings, very much in the shadow of what Building LA points out is "amongst the tallest residential buildings in the state of California.")

The giant glass-and-concrete building might help keep Downtown a little cooler too: when the 589-unit structure is completed, it's expected at certain times of the year to cast a shadow that will stretch across several blocks, all the way to Main and Seventh Streets…

more - http://t.co/B4z1ZZ2FOz

Cheers, Ralph

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