CLTC Study Finds TLEDs Lag Fluorescents in Performance

A recent study produced by Pacific Gas & Electric (PG&E) for the University of California-Davis’s California Lighting Technology Center (CLTC) adds quite a bit of useful data for those selling, specifying or installing LED replacements for linear fluorescent lighting. The study, “Linear LED Lamps: Application and Interoperability Evaluation,” revealed that LEDs are in many cases unsuitable replacements.

The study looked at lighting applications other than recessed troffers, for which research and testing data is already widely available. Instead it focused on comparing TLED performance in bare-lamp, pendant, wrap and direct/indirect fixtures and also examined interoperability with different ballast and driver options. The goal was to provide data on performance in less-than-ideal real-world applications, including studies on delamping fixtures.

The study examined and compared performance across several TLED lamp categories:

• Type A: Linear LED lamp with internal driver that is designed to operate on a linear fluorescent lamp ballast.
• Type B: Linear LED lamp with internal driver that must be connected directly to line voltage for power.
• Type C: Linear LED lamp with external driver that is designed to replace both the linear fluorescent lamp and fluorescent lamp ballast.

They also looked at dual-mode Type AB and Type AC lamps.

Among the more interesting results, the study found that TLED types A and B don’t provide equivalent performance except in a few specific applications, primarily in wrap fixtures. Type C lamps performed better than fluorescents except in direct/indirect fixtures. It found LEDs generally unsuitable for use in direct/indirect fixtures because their directional beam angles don’t match the 360-degree beam spread of the fluorescents they’re intended to replace. The study also emphatically stated that TLEDs should be used only with the specific driver equipment recommended by the manufacturer because running them on different drivers resulted in severely degraded performance.

Here's the study (in PDF): Linear LED Lamps: Application and Interoperability Evaluation