Rensselaer Polytechnic Institute - Articles and news items
Issue 2 2014 • 16 April 2014 • Jean Paul Freyssinier, Senior Research Scientist & Adjunct Assistant Professor, Lighting Research Center, Renesselaer Polytechnic Institute
Jean Paul Freyssinier provides a detailed summary of the Lighting Research Center – Rensselaer Polytechnic Institute’s work on understanding the useful life of airfield LED luminaires...
Issue 5 2012 • 2 October 2012 • John D. Bullough, Senior Scientist, Lighting Research Center, Rensselaer Polytechnic Institute
Light-Emitting Diode (LED) airfield lighting is increasingly used at airports in the United States and abroad, largely because of the potential for this technology to produce substantial savings in terms of maintenance and energy costs1. Information about LED lighting systems in terms of performance, cost, and other operations issues is not readily found in a single location. In an effort to gather information about airport experiences and feedback with LED airfield lighting, the Transportation Research Board (TRB) of the National Academies, through its Airport Cooperative Research Program (ACRP), appointed a panel of experts from airports, industry, government and academia to oversee a synthesis study, which has been recently published as ACRP Synthesis 35: Issues With Use of LED Airfield Light Fixtures. The objective of this synthesis study is to provide documentation about the performance of LED airfield lighting systems, and it is primarily intended for airfield operations managers and airport electrical maintenance staff.The detective work: The primary source of information for the synthesis was a survey of 22 airports and aviation agencies throughout the U.S. – including commercial, general aviation and military airports – conducted during the summer and fall of 2011. Airport managers and other individuals were asked about their experience with LED airfield lighting, and specific issues about installation, operation, maintenance, economics and their future outlook on this new technology.
Issue 6 2011 • 8 December 2011 • Jennifer Taylor, Lighting Research Centre, Rensselaer Polytechnic Institute, Troy, N.Y.
In the past two decades, the LED (light-emitting diode) has advanced to the point where it is now considered a key lighting technology, not only for its potential to save energy, reduce carbon emissions, and have a long service life, but also for its ability to be ‘tuned’ for optimal visual perception. For airfield lighting applications, technology performance and perception are equally important. In terms of technology performance, energy savings is a significant feature, but so too are the durability and longevity of the lighting system, which may have to operate under extreme weather conditions. In terms of visual perception, a lighting system’s light output, intensity, spectral distribution, and spatial and temporal beam distributions all affect the system’s salience and a pilot’s ability to perceive the light.Because LED light sources – semiconductors that emit photons – are inherently different from incandescent light sources, their performance and perception do not match those of incandescent lamps. Therefore, before LED lighting can replace incandescent lighting on airfields, two steps must be taken. First, it is crucial to determine whether LED systems can provide equal or greater technology per - formance and visual perception, in order to ensure safety, optimal life-cycle cost savings, and maintenance schedules. This step involves multiple levels of research, both in the laboratory and in the field, and should be conducted for many different types of airfield lighting applications and light source colours. Second, airfield lighting standards must be reviewed and changed as necessary to accommodate LED lighting systems, since existing standards were written with incandescent technology in mind. This step may involve changing fixture design requirements, such as thermal management system components or allowable light source colour boundaries and intensity levels, per research findings.
Issue 5 2010 • 1 October 2010 • Jennifer Taylor, Lighting Research Center, Rensselaer Polytechnic Institute, Troy, N.Y.
Advanced, energy-efficient lighting is one key element of global research to reduce energy consumption and carbon emissions. In just the last decade, the light-emitting diode (LED) has progressed from a small indicator light to a complete lighting system able to illuminate spaces such as an entire parking lot. LEDs promise much to be excited about: less energy consumption, reduced lifetime costs and maintenance, rugged design, “tunability”, and non-toxicity. However, implementing LEDs is not as simple as unscrewing one light bulb and replacing it with another.