| Early LED replacements for 4-ft, linear fluorescent T8 tubes don’t deliver sufficient light output to make them cost-effective SSL retrofits, but the products will get better along with LED improvements. | ||
The pitch is enticing. Replace your commonly-used 4-ft, linear fluorescent T8 tubes with LED-based solid-state lighting (SSL) technology and save money based on energy usage and maintenance. The long life and energy-saving attributes of LEDs have proven compelling in a number of applications. Unfortunately, early LED T8 retrofit products don’t deliver fluorescent-equivalent light output. Moreover the need in most cases to modify the fluorescent fixture – primarily the removal of the ballast – leaves both technical and regulatory obstacles to widespread LED tube deployment. Indeed LED T8s need a lot of work, but the products will improve as LEDs get brighter and manufacturers optimize both the optics and the drive circuits. Negative news of LED T8 tubes has arrived regularly and recently directly from the US Department of Energy (DOE). In yet another round of CALiPER (Commercially Available LED Product Evaluation and Reporting) tests, LED-based T8s performed far worse than fluorescent tubes. In his keynote presentation at Lightfair 2010 on May 11, DOE Lighting Program Manager Jim Brodrick stated, “We have yet to test one that works very well. [Relative to fluorescents you get] half the light output and half the efficacy.” |
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