As we've discussed in articles like this one, fluorescent lamps need something called a ballast to modulate the electricity flowing through them. These ballasts control the initial surge and ongoing energy required to run the lamp, protecting the lamp from being destroyed.
LED lights or lamps need the same kind of power management, and they normally use a device called a driver. These drivers can either be inside or outside the lamp itself. For instance, in common household LEDs, the driver is inside the lamp, or "integrated," so most people don't even know it's there. In a similar way, household compact fluorescent bulbs have integrated ballasts. This way, people have been able to replace their old incandescent bulbs without having to learn about ballasts and drivers.
Integrated drivers have definitely simplified many lamp replacements, but for businesses across the country using linear T8 fluorescent lamps (tubes) for general lighting, replacing lamps with LEDs was initially complex.
Let's look at an example to understand why. Picture an average T8 fluorescent lighting troffer in an office setting. Behind the troffer, you'd have one or more ballasts running the lamps. Since early LED tubes couldn't run on ballasts, replacing the fluorescent tubes meant removing both the lamps and the ballasts, then installing drivers (separate from the LED lamp) and the LED lamps themselves. This was both complex and expensive.
Today, however, LED T8 tubes generally don't run off external drivers anymore. So it's much simpler and more affordable to replace T8 fluorescent lamps with LED tubes. Here are the two primary options:
T8 LEDs and Ballasts
Many T8 LED tubes are now compatible with electronic fluorescent ballasts. In other words, the ballast works directly with a driver that is inside the LED, making installation is easy. Assuming the fluorescent lights you're replacing are run by an electronic ballast (rather than an old magnetic ballast), it's a light bulb swap like any other. With the power shut off, you simply remove the old fluorescent lamp and replace it with the LED lamp. Just like that, you're running on LED.
Make sure to check the LED specifications, though. Some only work with instant start electronic ballasts, while other work with both instant start and rapid start models. Rapid starts are generally used anywhere you have an occupancy sensor, and could be used elsewhere.
Of course with this simple approach, you may be using a ballast that's already put in a lot of hours. That means it may die long before the lamp and will eventually need to be replaced.
Direct Wire T8 LEDs
As we already explained, most T8 LED bulbs have drivers built inside them, including those that work directly off of ballasts. Some, however, are designed to work without a ballast and are wired directly into the power source.
So if you're replacing T8 fluorescent lamps with one of these, you need to remove the old lamps and disconnect the ballast(s), then hardwire the fixture to the power. You can then install the LED tubes and, from then on, if you ever need to replace one of the lamps (probably 50,000+ hours later), it's an easy light bulb switch.
The disadvantage to this is obviously the extra work in the beginning. The advantage is that you're no longer dependent on external ballasts.
T8 LED Hybrids
At the time of this writing, there's a newer option of T8 LED also available. It allows a direct retrofit, running off ballasts that are already installed (like the first option above); then when the ballast eventually fails, the ballast can be disconnected and the lamp can then be hardwired (like the second option above). In short, it's both options in one T8 LED lamp.
The Advantages of T8 LED Tubes over T8 Fluorescent Tubes
So why bother to upgrade to LED lighting anyway? Fluorescent tubes are inexpensive and, by common standards, efficiently produce quality light. Well different people will have different reasons for moving to LED, but here are some things to consider:
* While modern fluorescent lamps have minimized the amount of mercury needed to produce light, they still do have mercury in them. This is considered a toxic substance, making a broken bulb something of hazard. LEDs do not use mercury.
* Fluorescent lamps can last a very long time, and if you're willing to pony up for longevity, some of them might even outlast an LED. But generally speaking, a fluorescent lamp will last 24,000 to 30,000 hours while an LED will last around 50,000. This nearly doubles the replacement cost for fluorescents in both the physical lamp and maintenance costs over time.
* LEDs are notoriously the most efficient lights available, but fluorescent lights are a close second in terms of lumens (amount of light) per watt of energy used. So in the case of a standard household bulb, for instance, a 60 watt incandescent bulb might be replace by a 13 watt CFL (compact fluorescent light) or a 9 watt LED. Not a huge apparent difference in wattage between the fluorescent and LED (probably under $1 a year in energy use.)
But when it comes to light tubes in a troffer, the energy savings are more substantial. This is because fluorescent tubes send light in all directions; some of this has to be reflected back toward a working surface from the troffer itself. This is an inefficient use of lighting. LED lights, on the other hand, are directional, and send all their light toward the working surface. This is why a T8 LED with nominally fewer lumens (less light production) can replace a T8 fluorescent lamp that produces more lumens.
For instance, you might see a 15 watt LED tube replace a 32 watt fluorescent tube. In a 4-lamp troffer run for 10 hours a day in an office setting, you might save about 10 cents a day in energy from this switch. If that doesn't sound like much, remember that it's close to $40/year, which might entirely cover the initial cost of those LED lamps. After that, every year those savings would go into your business rather than into electricity.
* LEDs offer more and better dimming options.
* The lifespan of an LED isn't shortened with frequent on/off switching, making them a better fit with occupancy sensors -- another tool for saving money over time.
Fluorescent tubes may still be popular for a time: they're familiar, affordable, and easily matched when replacing a lamp that's gone out. But LEDs have finally gotten so affordable that they can pay for themselves quickly, and with new "ballast compatible" LEDs, they've become an easy retrofit option. So what will your business do? Are you ready to make the switch to LED?