T5 fluorescent was developed in Europe about 12 years ago and was initially used as a means to make diminutive indirect luminaires. The source is compact (only 5/8" diameter), but the High Output version packs a punch with 5,000 initial lumens for 54 Watts. That's why it's capable of being used at 'highbay' mounting heights. And, it maintains 95% (ninety-five percent!) of that output over its entire life.
Read more about T5 efficiency or download the PDF
And it's a long life
When the source was new, lamp manufacturers used accelerated life testing to estimate an average expected lamp life of 20,000 hours. But real life experience shows that this is much too low, and lamp manufactures have re-rated life ratings to 40,000 hours.
Read more about lamp life or download the PDF
What about light quality?
Glad you asked. It comes in 3000K, 3500K, 4100K, and even ultra-cool appearing 5000K & 6500K for those who desire a brighter "appearing" light source. T5 has a CRI (color rendering index) of 85, which is excellent (standard metal halide is only 65CRI). Colors just look great under this lamp.
Read more about color and light or download the PDF
So what's all the talk about temperature performance?
This source produces its optimum light output at 95°F (ambient temperature relative to the bulb wall, not the space it's in). This is 18 degrees warmer than conventional sources, which means it will produce more light in a warmer environment, and will sustain it's bulb wall temperature better in colder settings; this gives it an effective operating window of -20°F up to 165°F, which is very competitive with HID. T5 performs very well in Hot or Cold environments, particularly in well-designed and engineered fixtures like those from The Light Edge, Inc.