Like mercury vapor lamps, fluorescent T12 lamps have seemed to disappear. While the T12 was once the inexpensive alternative to incandescent bulbs, the more efficient T8 and T5 lamps have since replaced the outdated technology. In order to comply with Department of Energy (DOE) regulations, T12 lighting has been phased out for the energy efficient alternatives. Magnetic ballasts most commonly used for T12 lamps ceased production in July 2010 and T12 lamps haven’t been manufactured since July 2012.

But what’s the difference between T5, T8, and T12, anyway?

The “T” stands for tube or tubular. The number represents the diameter of the tube. T12 is the largest lamp (1.5″), followed by T8 (1″) and T5 (5/8″). T12 lamps are run on less efficient magnetic ballasts whereas T8 and T5 lamps are run on electronic ballasts. Because of the magnetic ballast and inefficient lamp size of T12, T8 and T5 seem to be the obvious choice for fluorescent lighting.

Contact an Access Fixtures’ lighting specialist to learn more.