T8 LED tube lights (TLEDs) are used to retrofit T12 and T8 luminaires. Conversion to TLED from T12 has rapid return on investment as the chart in an earlier blog demonstrates. TLEDs are available in two very different operating formats. There is the type like Access Fixtures T8 LED Tube Lights that have an internal driver and work on 120v to 277v line voltage. There is also the type that requires a T8 ballast like Philips InstaFit LED T8 lamps. The case for TLEDs with internal drivers is fairly simple. But can a case be made for TLEDs that require a T8 ballast to operate?
First, here is the case for TLEDs with an integrated driver. TLEDs with an integrated driver are lower cost and easier to trouble shoot if there is ever an issue. TLEDs with an internal driver require more upfront labor, the removal of the old ballast and some rewiring. The additional labor adds cost, but the resulting simplicity and savings are worth it. Should the TLED with an internal driver ever stop functioning, the problem is easy to define. It is either the power supply to the luminaire or the TLED. Either can be easily addressed.
The InstaFit type TLED potentially has an easier initial installation, but installation of new TLEDs that require a T8 ballast should be accompanied by the installation of new ballasts. Using an existing ballast means the ballast will most likely fail long before the TLED fails. In this case, if the TLED stops functioning, it is more difficult to determine the point of failure. Is it the power supply, the ballast or the lamps? The T8 ballast adds significant cost if it is installed new, or if it is replaced each time one fails and there is a service call. OUCH!
So, can a case be made for T8 LED lamps that require a T8 ballast? Yes, but it is only due to legislation and the case can only be made in the state of California. In California, retrofitting existing fixtures with reduced wattage fluorescent TLEDs, while keeping the existing ballasts, does not trigger Title 24. Title 24 permits installation of TLEDs that require a T8 ballast, but if you were to change to TLED with integrated drivers, you would be required to bring the entire facility up to Title 24 standards.
Previously, Title 24 retrofit projects did not have to meet the same standard as new construction. Now the standards are the same, and naturally what is okay for new construction is not often cost-effective for retrofits. For instance, Title 24 retrofits now require bi-level lighting and controls to support that in almost every fixture unless the lighting powder density (LPD) is less than 0.5 watts per square foot (WSF), increasing retrofits cost by 20 to 30% more. That is expensive and has a very low ROI.