LED tubes are a promising solution if you are looking for quick and simple building upgrades that reduce energy consumption. It is possible to achieve significant improvements in lighting efficiency, while keeping the existing fixtures and minimizing upgrade costs. LED tubes also provide a simple way to meet Local Law 88 of 2009: all buildings covered by the law must have lighting systems that meet the NYC Energy Code by 2025.
However, before replacing conventional fluorescent tubes with their LED counterparts, it is important to select the right type of tube. There are three main types, each with advantages and disadvantages, and a different connection procedure:
UL Type A - Designed for the fluorescent lighting ballasts in existing fixtures.
UL Type B - Designed for direct connection to the power supply (no ballast).
UL Type C - Designed for use with an external driver that only works with LED.
UL stands for Underwriters Laboratories, an organization that certifies electrical products for safety. Always use electrical equipment with the UL mark to minimize the risk of fire.
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UL Type A: LED Tubes for Existing Ballasts
LED tubes that are classified as UL Type A are the easiest to install, since they are designed to use the same ballasts as conventional fluorescent tubes. It is only important to check compatibility between the existing ballast and the proposed tube before purchasing a large batch. Also note that Type A LED tubes are normally designed to replace a specific type of fluorescent tube: T12, T8 or T5. For example, you can replace a T8 fluorescent tube with a T8-equivalent LED tube, but not with aT5-equivalent.
The main limitation of these LED tubes is dependence on ballasts that were designed for an older technology:
Although energy savings are significant, the power loss associated with the ballast remains.
In addition, these LED tubes are also limited in dimming and control options; any control system proposed must be compatible with the fluorescent lighting ballast.
Lighting upgrades that use Type A LED tubes can also be demanding in terms of maintenance. While the LED tubes last 2 to 3 times longer than their T8 fluorescent counterparts, the maintenance requirements of the ballasts are the same; the tubes last longer, so you will eventually have to schedule a ballast replacement. Also consider that replacing a ballast involves opening the fixture and disconnecting many of its internal components, which can be disrupting in certain commercial locations such as offices.
UL Type B: LED Tubes for Direct Connection to the Power Supply
This type of LED tube has a built-in driver, designed for the voltage supplied by the utility, which means the ballast can be bypassed completely. As a result, if you use them in a new construction or major renovation, there is no need to purchase and install ballasts at all.
However, the upgrade can be labor-intensive in an existing installation, since existing ballasts must be bypassed and the lamp bases must be normally changed. Many T8 fluorescent lamps use bases where both pins are connected together (shunt connection), while direct-connection LED tubes normally use isolated bases (non-shunted). You can expect higher efficiency from Type B LED lamps, compared with Type A, since the power loss of the ballast is eliminated from the system.
Of course, Type B LED tubes also have certain disadvantages that must be considered:
Working safely is very important in any electrical installation, but extra caution is required with Type B LED tubes, since the supply voltage is present at the connection pins. In other lamp configurations, the connection pins only have the reduced voltage output of a ballast or driver.
Since Type B LED tubes have all the power-conditioning components built in, there can be plenty of localized heat. As a result, these lamps tend to have a shorter service life than other options.
These LED tubes are the most sensitive to voltage disturbances, since the reduced scale of electronic components leaves less space for protection features.
Automatic control options are also limited for these lamps.
UL Type C: LED Tubes with a Dedicated Driver
Type C LED tubes have an external power conditioning unit called a driver, with similar appearance to a ballast, but designed specifically for LED to maximize performance. As a result, Type C lamps deliver the most lumens per watt consumed among the three types of LED tubes.
Since an external driver provides more space for electronic components, the Type C LED tube configuration offers the most protection against voltage disturbances. It also offers good compatibility with automatic controls such as dimmers and occupancy sensors. Consider that the NYC Energy Code establishes many automatic control requirements for commercial lighting installations, making these tubes a solid choice to meet both efficacy and control requirements.
Type C LED tubes are generally the best solution in terms of performance and durability. Their main drawbacks are the extra cost of the ballast and the installation complexity. Just keep in mind that these LED tubes may vary in their connection method:
Some Type C LED tubes use a direct connection with the driver, and lamp bases only provide mechanical support.
Others are connected just like fluorescent tubes, where the lamp bases provide both mechanical support and a voltage supply.
The advantage of a direct connection between the driver and tubes is that the type of lamp base becomes irrelevant, as long as it isn’t damaged physically. On the other hand, if you use Type C tubes that are powered through the lamp bases, you must check compatibility.
Combined UL Type A & B: Hybrid LED Tubes
Some lighting manufacturers offer LED tubes that can operate with either a ballast (Type A) or a direct connection (Type B). Their main advantage is versatility.
To upgrade an existing installation, they can be connected using the fluorescent lighting ballasts.
As ballasts reach the end of their service life, the lighting fixtures can be re-wired for a direct connection to the power supply, with no need to purchase replacement ballasts.
These hybrid tubes can be a good option for installations where the ballasts are compatible but already a few years old - once they reach the end of their service life, the lamps are simply switched to a direct connection.
LED lighting upgrades are among the simplest energy efficiency measures for commercial buildings. They save energy directly with reduced power consumption, and indirectly when air conditioning equipment is used, since there is less lighting heat to remove. However, with such a wide range of LED tubes in the market, product selection is very important - an engineering consulting firm can help you find the best upgrades, not only for lighting fixtures, but for all your building systems.
At Nearby EngineersNew York EngineersMintropy, we search for simple, eloquent solutions to complex problems. We minimize construction costs by eliminating the extraneous and focusing on the overall efficiency for the most streamlined designs.