LEDs also offer increased light efficiency when dimmed as opposed to T5 fixtures and usually produce more lumens per watt in general, which decreases energy usage and thus, energy costs. A lower wattage of LED luminaire will usually be just as efficient, sometimes more, as a higher wattage T5 lamp.
Description
Specification
The "T" refers to "tubular," which is the shape of the bulb, while the number represents a fraction in eighths of an inch. This means a T5 bulb is tubular and is 5/8" in diameter, while a T8 bulb is also tubular and is 8/8" (meaning 1") in diameter.