April 4, 2012
TRA-Mage, Inc., manufacturer of solar racking systems, questioned whether the theoretical calculations determining rail spans would be validated under real world tested conditions. Field tests were performed and found to greatly exceed theoretical values allowing for an improved TRA-Mage span standard.
TRA-Mage’s solar mounting and racking products consist of many integrated components to mount solar panels to the roof or ground. In order to offer high quality products that will withstand harsh weather conditions, and perform well for many years; every solar racking system gets a full engineered review per the project’s specifications. Wind load, snow load, building height, exposure category, and other factors are considered. Until recently, the calculations of these factors were based on engineered calculations rather than actual field tests.
Aaron Disbrow, Technical Department Manager, explains, “Several customers brought to our attention the spans of other systems, but still preferred our overall system. These comments led our technical team to develop rail span testing with modules incorporated which improved the rail spans for all our solar mounting solutions.”
Various sizes of rails were tested including 40 x 60 mm, 40 x 40 mm and the 22 x 65mm. The *results of the tests revealed a significant increase in actual strength compared to theoretical calculations. The 22 x 65mm rail proved to be the strongest, which results in safely increasing spans between fixed mounts from an average of four feet to six feet. This results in less mounting components needed – typically a 33% savings. Using the 22 x 65 mm rail also saves an additional 18% when compared to the larger 40 x 60 mm rail. TRA-Mage engineers now use the, the 22 x 65 mm mounting rail almost exclusively for all solar racking solutions (fixed mount, elevated frame and ballasted frame) resulting in savings for almost every customer.
In addition to the rails, the field tests also revealed other savings for solar customers using TRA-Mage’s Ballasted System. Ballasted systems use rails and ballast blocks. A review of the engineered ballast weight requirements, led to a reduction in the amount of ballast required to effectively secure a ballasted solar system. An average weight reduction, results in a 28% savings. In addition, less load is placed on the roof, decreasing the overall load and making more retrofit installations possible. For example, this makes all the difference when installing solar on older buildings that lack the structural support of today’s newer construction.
Disbrow summarized, “We’re always trying to find the best solution for our customers. Our technical team was pleasantly surprised to find a way that we could provide a sound and strong system which resulted in savings for our customers.”
*All testing results were verified by a licensed engineer.
TRA-Mage, Inc., located in American Fork, Utah, offers Roof Snow Retention Devices, Solar Racking Systems and Roof Flashing Solutions. They provide to all customers, from the individual homeowner to the big developer, free engineered designs for all their systems. For more information call Jacob Anderson at TRA-MAGE at 800-606-8980 or visit snow.tra-mage.com