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Home > Resource Conservation > ElectricityLight Bulbs > Conversion of T12 to T8 fluorescent light bulbs

Conversion of T12 to T8 fluorescent lighting.

T8 LED bulb
     Many business (and homes) still have T12 lighting technology in their facility. We will discuss the advantages and drawbacks of changing to a T8 light fixture here.


    The T12 Fluorescent Bulb and Fixture: Several decades ago a new technology emerged that helped many factories become more efficient. The technology was called fluorescent bulbs. This technology saved about half of the lighting costs of a facility and had a long life (10 to 20 times) compared to what was being used before.
     The T12 bulb was one of the more common bulbs used for this technology. This is a glass tube 1 1/2 in. in diameter and came in lengths of 8', 4' and a few more lengths. The bulb contains Mercury to make the light and requires a ballast to condition the power supplied to it. This saved the country a lot of power use when it came out.
     The question is, why fix it if it ain't broke?
     This is not just a question of efficiency but one of disposal and labor costs.
      The T8 Fixture: First of all, you do not need to change out the fixture to put T8 bulbs in them. Both bulbs have 2 pins at the ends of the bulb that fit into the same fixture. The big difference is in the ballast. 
     The ballasts: If the T12 fixture is really old the ballast may contain PCBs'  (Polychlorinated biphenyls) considered a toxic substance and banned in 1976. The T12 bulb requires the use of a magnetic ballast. The T8 requires the use of an electronic ballast. Therefore, even though you can use the same fixture, you can not use the same ballast. We suggest that you dispose of the ballasts and T12 bulbs responsibly. Sometimes when your bulb burns out your ballast does to, so you may want to add a small amount of money to your replacement costs.
     Energy Savings: It may be surprising how much energy you will save. The bulbs themselves will have nearly the same wattage rating. You may go from 40 Watt down to 32 Watt bulb but saving about 50% electricity consumption. This is due to the replacement of the ballast (they consume power as well). The T8 bulb tends to last a little longer than a T12 bulb as well. The approximate lifetimes for T12 is 20,000 hours and T8 is more like 30,000 hours. Which is also an energy/labor cost savings.
     Disposal/Recycling: There is little recycling of this type of bulb/ballast. However, these things contain toxic material. Both T12 and T8 contain Mercury but the T8 bulb contains a little less. Both will need to be disposed of properly.
     Costs: T12 bulbs may cost a little less than T8 bulbs, but you have to also look at how often you have to replace the ballasts to determine the costs. Many utilities have rebate programs to help defray the costs of conversion. Click here to find rebates in your area. Some utilities can help quite a bit but may insist on proper disposal of bulb/ballasts.
When you have researched the costs, feel free to use the "green calculator" below to determine feasibility.
     As always we recommend  that you follow instructions carefully or obtain the services of an electrician before converting your light fixtures. You can go to our services section to help find an electrician.

Our recycling/garbage  section may help you find a place for the ballasts/bulbs you plan to throw away.


An Alternative, T8 LED Light Bulbs:
    New to the market are T8 replacement bulbs that are based on LED technology. This can increase your energy (cost) savings while decreasing your disposal headache.
     The "ballast" for this type of bulb is built into the bulb, therefore you will need to bypass or remove the current ballast in your fixture. The bulb comes in many of the same colors that current Fluorescent bulbs come in so your light rendering can be nearly the same or better with these bulbs.
     These bulbs have a projected life time of 40,000 hours (at 24 hour operation that means about 5 years)
    Cost for the each bulb may be a little high but you should use the "green calculator" below to determine feasibility. We think you may be surprised by the return on investment. Also, your utility company may provide rebates for this type of T8 technology.
    Some lighting retailers have avoided selling these lights because some of the problems for these bulbs living to full expectancy. That can be a risk but if you make your calculations on Return on Investment and find that it is a short time, longevity may not be as big of an issue while this technology develops.  You may go to Greencompletely.com's Amazon.com Store to find these bulbs. We believe Eagle Lighting to be a reputable supplier of these bulbs.