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Replace T12 fluorescent lamps with T5 or T8 bulbs

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Replacing your T12 bulbs with T8 or T5 bulbs reduces your office’s energy consumption, prevents the use of toxic chemicals (contained in older style bulbs), and reduces air conditioning costs. It may also increase employee productivity since newer bulbs generally provide more natural light.

Find it! T5 or T8 bulbs

Converting your T12 lighting fixtures to T8s or T5s requires replacing the entire existing fixture. While this might seem complicated and costly, with rebates and inevitable energy savings, such a retrofit is well worth it.

Most major lighting companies now carry the following energy-saving bulbs:

Replacing your T12 bulbs with T8 or T5 bulbs helps your office go green because…

  • They save energy.
  • These bulbs require fewer toxic chemicals.
  • They emit less heat (thus reducing air conditioning costs).[1]
  • They provide better quality light.[2]

Office lighting is an important consideration for businesses, since it can have a significant impact on the efficiency of staff. The wrong amount or kind of light can result in eyestrain, glare, and headaches, which in turn can decrease employee productivity.[3] The most energy efficient solution for office lighting is always daylighting (designing rooms to optimize natural light). But when windows are scarce, energy-efficient electric lighting options are available.[3]

Lighting, both indoor and outdoor, is one of the biggest energy drains in office environments. It accounts for nearly 28 percent of total office energy consumption.[4] Most fluorescent light fixtures that are older than 10 years use T12 lamps, which are 1.5-inches in diameter and come in 4- or 8-foot lengths. New high efficiency T-8 lamps, which are 1-inch in diameter, use 40 percent fewer watts, produce 40 percent less heat (which is important in warmer months when air conditioning is needed), and output 10 percent more light.[5][6]

Even newer are T5 lamps, which are five-eighths of an inch in diameter and are 10-15 percent more efficient than T8s.[5]

Businesses can also achieve energy savings by replacing old incandescent light bulbs with CFL bulbs, choosing LED bulbs for exit and exterior signs, installing occupancy sensors and dimmable lights, and by simply turning lights off (especially at night) when rooms are not in use.[3]

Tax breaks and subsidies

Most states have at least one listing on the Database of State Incentives for Renewables & Efficiency. Choose the ‘Search by’ option, then ‘Technology,’ and then choose 'Lighting’ to find out if your business qualifies.

External links



This article states many good reasons for retrofitting old T12 lights to newer T5 bulbs, but I would like to list a few more benefits. First, switching to T5 bulbs allows you to use only 2 bulbs in a fixture instead of using 3 T12 or T8 bulbs. This cuts energy consumption in addition to the 4-12 watts that is already saved per bulb as a result of increased efficiency. T5 bulbs also have a much lower lumen fallout (<5%) than T12/8 bulbs (≥10-30%), which means that T5 bulbs put out roughly the same amount of light after 20,000 hours as when they are first installed.

If you are seriously thinking about retrofitting your lighting system, I suggest researching T5 bulbs further. The one major downside of T5 bulbs is that they do not naturally fit into fixtures designed for T12 or T8 bulbs . Luckily, the company I work for has come out with a UL certified adapter that makes it easy and cost-effective to install T5 bulbs into T12 and T8 fixtures. You can find more information on our website at

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