5 Types of Fluorescent Light Bulbs Explained

Fluorescent light bulb technology has exploded in the past decade, in part owing to its favorable energy consumption profile. In comparison to traditional bulbs, fluorescent options generate much less heat and last much longer. And as design, production technology, and demand have increased, costs have dropped dramatically, making fluorescents the first choice for many situations. Following are the five most common types of bulbs.

Compact Fluorescent Light (CFL)

CFLs have really taken over the marketplace and are available in many styles and socket sizes, designed to replace incandescent bulbs. CFLs screw in to regular sockets, are self-ballasted and require no special power arrangements. While the initial investment is roughly double that of incandescents, CFLs consume about 80% less energy and last 400-500% longer. The color rendition index (CRI) of CFLs has also broadened, so they are available from soft daylight (2700k) up to bright sunlight (6500k), offering natural or brilliant light as needed.

Traditional Tubular Fluorescent (T12)

T12 lights are the standard tubular fluorescent used in most workshops, businesses, and classrooms. They are a very inexpensive solution to lighting large areas. Dual-tube suspended fixtures cost as little as $10 each, and the replacement tubes are only a few dollars each, even cheaper in bulk. Bulbs are available in a wide variety of CRI, lumen output, and special application designs (shatter resistant, low temperature, etc). They have a two-pin connector and require a ballast/igniter to start.

High Output Tubular (T5, T8)

For instances where a better lumen output per watt ratio is required, high output fluorescents are indicated. Where a typical 40-watt T12 bulb might generate 2200 lumens, a T5 would output 4000 lumens. These lights look like standard T12, but the tubes are smaller in diameter. Some common uses are saltwater aquarium lighting, indoor horticulture, commercial lighting, and light treatment for seasonal affective disorder. High output bulbs do not fit in standard T12 fixtures, and require a different type of ballast.

Circiline

Circiline fluorescents are bascially a small tubular bulb fashioned into a circle. They came into popularity as a replacement for the heat-producing halogen torchiere lamps that were implicated in home fires. Circiline bulbs naturally focus light in a cone, require a special plug and ballast and are not interchangable with any other type of fluorescent.

Cold Cathode Fluorescent Light (CCFL)

The latest development in fluorescent bulb technology is the CCFL, a low-wattage solution that is most often used to light electronics, but is gaining ground as a consumer solution and is poised to overtake CFLs once production volumes and design efficiencies reduce their cost. CCFLs use a highly efficient inverter to power small gas-filled tubes that can be practically any color and any shape. CCFLs are dimmable, retain their CRI when dimmed, and have an extremely long life cycle: 18,000-25,000 hours!