It’s tough to argue the energy efficiency of LEDs, but other needs that can dramatically impact occupant satisfaction – for example, a reputation for “white” light that isn’t truly white – can scare away buyers.
However, the technology has improved over the years even as the price has dropped, making these systems worth a look for FMs looking to reduce their energy spend. Compare these performance factors when weighing products.
This rating for lumen output per watt is an easily measurable metric that compares the energy consumption and output of different light sources, explains Eric Lind, vice president of global specifications for Lutron Electronics, a lighting control designer and manufacturer. However, he adds, it’s starting to lose its relevance in favor of overall performance measurements.
“If I’m simply trying to evaluate how much it costs to operate a building, lumens per watt is a good measurement,” says Lind. “The challenge is that buildings are there for a purpose and the color and quality of light have an impact on the people inside.”
CRI measures how accurately light sources display colors and is determined by comparing a colored object’s appearance under an incandescent light (which has a CRI of 90-100) vs. an artificial source.
ENERGY STAR requires eligible fixtures to use lamps with a CRI above 80, but the closer you can get to the 90s, the better, Lind says.
The option of changing light levels (and in some cases, color temperature) to suit individual needs can go a long way toward satisfying users while saving energy.
A more recent development, a color dubbed “tunable white,” offers the chance to alter the color temperature.
“Tunable white is the premise that the color temperature can change based on what is typical for that time of day,” explains Lind. “At noon, the temperature might be 6000K, but in the morning or at sunset it would be a much warmer 2700 or 3000K.”
Janelle Penny firstname.lastname@example.org is senior editor of BUILDINGS.