Linear Fluorescent Lighting

What are Linear Fluorescent Lights?

Linear fluorescent lighting refers to the overhead tubular fluorescents often found in businesses, governmental agencies, hospitals, garages and kitchens. They can come in many diameters, lengths, shapes, and qualities but they all operate on the same basic principle: electricity excites mercury atoms which then release ultraviolet photons. These photons then pass through a phosphorous coating which turns the ultraviolet energy into a visible light spectrum. 

Linear fluorescents are commonly referred to by their diameter, as they are measured by 1/8 inch increments. You may hear reference to a T12, T8 or T5 fluorescent, the T refers to tubular and the digit refers to the diameter. That means a T12 is referencing a tubular fluorescent that is one and half inch in diameter and a T8 is referencing a tubular fluorescent that is one inch in diameter. Linear fluorescents can be of varying lengths but the most common are four and eight feet.

All fluorescent lighting (including compact fluorescents) require a ballast to operate. Ballasts work to control electrical current as it passes through the fluorescent tube. The two main types are magnetic and electronic ballasts. Electronic ballasts are more efficient than magnetic ballasts. Redwood Coast Energy Authority recommends using a NEMA Premium ballast and a licensed contractor when updating from T12 magnetically ballasted fluorescent lamps to new T8 technologies.

Not all Linear Fluorescents are created equal. T12 fluorescents operating on magnetic ballasts are significantly less efficient than T8 lamps operating on electronic ballasts. Consumers can save up to 35 percent of energy used by replacing T12 lamps and magnetic ballasts with T8 lamps driven by electronic ballasts. But that's not the only advantage of T8 fluorescents and electronic ballasts. By using electronic ballasts with T8 lamps you will notice a significant reduction if not elimination of the common flicker and hum associated with T12 fluorescents. In addition, T8 lamps and electronic ballasts often offer much better color rendering. The end result of a T12 to T8 retrofit is a much more enjoyable, well lit space.

The Redwood Coast Energy Watch offers free lighting assessments, enhanced incentives and turn-key project management for PG&E consumers on commercial rate schedules. RCEW can help you retrofit your existing T12 linear fluorescents to the more efficient T8.

As noted above, linear fluorescents contain mercury. Because all fluorescents depend on mercury to emit ultraviolet radiation the Redwood Coast Energy Authority (RCEA) recommends and specifies the purchase of low mercury content T8s when retrofitting existing fixtures. In addition, RCEA encourages you to properly dispose of your failed linear fluorescents. Humboldt residents can take advantage of the free Take it Back program.