Six Common Questions About LED Retrofits
Not long ago, it was understood that you could gauge the brightness of an incandescent bulb ased on the wattage listed on the box. People
knew instinctively how many 60- or 75-watt bulbs were
needed to light a living room, and similarly how many
450-watt high-intensity discharge fixtures were needed
to light a warehouse. However, watts are not a measurement of brightness, they are a measurement of energy
use. As lighting becomes more efficient, brighter lights
use fewer watts, which makes the correlation most
people relied on for years less and less relevant.
Similarly, the size of fluorescent tubes and fixtures has
long been the yardstick for measuring brightness and
light distribution. Once again, due to inherent differences
between fluorescents and LEDs, asking how big a fixture
is won’t adequately answer questions about LEDs except
the literal one: How much space will it occupy?
Using outdated concepts to determine which fixture to
install is like comparing smartphones and landlines based
on their number of buttons. Those who become familiar with the features and cost requirements of LEDs will
be better able to decide what type of fixture will help a
facility reach its foot candle requirements, energy savings
and other goals. Each warehouse and distribution center
has different needs, but the direct, bright light produced
by LEDs is uniquely beneficial when compared to older
lighting technologies. Below are some common questions
about LED upgrades.
Q: What Is An LED Anyway? LED stands for light-emitting diode. Rather
than an electric arc or delicate filament, LEDs create light
by passing electrons over a tiny, flat semiconductor. For
half a century, LEDs have been used for small indicator
lights in consumer electronics like computer keyboards
and telephones. Thanks to their low heat production,
negligible energy use, long life and durability, they were
prized for enclosed devices that aren’t intended to be
disassembled. Only in the last decade or so has LED tech-
nology advanced to the point where it can efficiently pro-
duce bright, white light ideal for room and task lighting.
Q:How Many Bulbs Do LED Fixtures Use, And How Often Do I Have To
None, and never. Unlike traditional bulbs, LEDs don’t
abruptly burn out; instead, they slowly dim over a period
of years or decades. Life cycles vary, but premier fixtures
have an average rated life of 130,000 to 150,000 hours.
The average rated life of an LED is the time it takes to
reach 70 percent of its initial brightness, so the overall life
of the fixture could be much longer. Still, 150,000 hours
equates to 17 years if the fixtures are in use for 24 hours a
day, which is a long time to go without a bulb change.
Q: If Watts And Size Are Useless, How Do You Measure Brightness?
Lumens are the actual measure of brightness, and
they’re slowly becoming the accepted form of expressing
the effectiveness of bulbs and fixtures. The Federal Trade
Commission started requiring lumen output to be includ-
ed on the packaging of most lights in 2012. However, to
those unfamiliar with the term, it’s a meaningless number.
Lumen output varies by make, model and manufacturer,
By Josh Kegley