T5 Vs. T8 Fluorescent Lights

Fluorescent lights are classified by wattage, shape and diameter. The "T" in T5s and T8s refers to the tubular shape of the bulb, while the number refers to its diameter. Their light output is measured in lumens. Older fluorescent lights, like T12s and T38s, use a process called electromagnetic induction to produce light. However, this is less efficient than the latest technologies as of 2010; newer T5s and T8s use more efficient, cost-effective methods.

  1. T8 Basics

    • T8s are considered the predecessor to the T5, though they are available with the newer lighting technologies (versus electromagnetic induction). T8s run on less mercury than the older fluorescent bulbs and also flicker less, are quieter and produce less heat than standard T12s. T8s have consistent light output, as well.

    T5 Basics

    • T5s are 40 percent smaller than T8s, but can contain as much or even more light in the same area. A high-output, 4-foot-long T5 bulb with a lumen rating of 5,000 can produce twice the light as the same size T8 bulb. That means it would take more T8 fixtures than high-output T5 fixtures to get the same amount of light.

    T5 vs. T8 Cost, Maintenance and Availability

    • The newer T5s are more expensive than their T8 predecessors, but they're also more efficient and lower maintenance. This can translate into overall, long-term savings on commercial and residential structures and projects---especially large-scale examples. However, T5 and T8 bulbs and fixtures are still widely available in 2, 3, 4 and 5-foot lengths as of 2010.

    Uses

    • T5s and T8s are used in new constructions, such as housing, commercial and industrial structures, though they are more common in commercial and industrial buildings than residential ones. T5s are becoming more common due to their many benefits and are also used for other purposes, such as in fish aquariums, terrariums (particularly for exotic desert-dwelling reptiles like tortoises, geckos and pythons), desk lighting, display lighting, indirect lighting, backlighting, task lighting, trade show lighting and medical settings.

    Fluorescent Lighting Technology

    • Because fluorescent lights are more efficient and generally more cost-effective in the long-term than incandescent bulbs, they are becoming more popular in a variety of forms. Compact fluorescent lights (CFLs) are the everyday home versions of T8s and T5s in that they use efficient fluorescent lighting technology and are fitted for lamps and other light fixtures that are common in residential homes and would customarily use incandescent bulbs---unlike T5 and T8 bulbs that need specific fixtures.