ARTIFICIAL LIGHTING
Bars come in a number of different
lengths and profiles, consume low
to medium amounts of power at low
to medium intensity, and use space
efficiently. Panels (shaped like a slender
box) offer low to medium intensity and
use low or medium amounts of power,
similar to bars. This type of lighting
tends to be more expensive than bars
but offers better coverage.
Heat Outputs
Despite the efficiency of LEDs, they
still produce significant heat. In
confined growing environments
with lots of light, this means a
lot of HVAC costs. One common
misconception is that LEDS
eliminate this expense. While LEDs
do reduce the cost of heat removal,
the cost still exists and increases as
growers increase growing density.
The cooler LEDs are kept, the more
efficient they are, and the longer they
last. Heat removal impacts the design
of fixtures, panels and bars. LED
designers and engineers have several
options for cooling LEDs. They use:
• Low-powered LEDs to keep the
heat produced to a minimum.
This approach is common in bar
and panel design and typically
limits these techniques to lower
light demand crops, like lettuce.
• Complicated extrusions or fins
to increase the surface area and
ability to dissipate heat from light
to air. This approach is common
in bar and fixture design, but
adds to the overall cost.
• Fans and forced convection to
circulate air. This approach is
most common in fixtures, which
have the bulk to house fans, and
is the most effective heat-removal
option of the three.
Warranties &
Efficiency Ratings
When choosing an LED lighting
system, it is important to pay
attention to both years and hours
listed on light warranties. Lifespans
may be listed in years, but that
number is sometimes based on a
calculation using a low hours per
day operation time. There are
also often different percentage
efficiency ratings on warranties,
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meaning that one manufacturer
may warrant to 70% efficiency at
70,000 hours, while others warranty
to 90% efficiency at 50,000 hours.
Growers benefit from reading the
small print in this case. Growers
may also benefit from reading the
product’s component replacement
agreements. Because LED arrays are
often manufactured in large units
rather than separate, removable
parts, one malfunctioning piece
may require the replacement of the
entire lighting array.
W
hen choosing the best LED
lighting system, you need to
consider all of the contributing
factors outlined here. Starting or
scaling a profitable farm can be like
running your first marathon. All the
pain and preparation required to
be successful can feel overwhelming
at times, but the feeling of
accomplishment and increased
strength when you cross the finish
line makes it all worth it.
For a FREE lighting calculator visit
able.ag/calculators.
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“Production of useless wavelengths consume energy but do not result
in photosynthesis. Less efficient lights produce more heat, and high
temperatures reduce the efficiency of the light, and its lifespan.”
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Maximum Yield USA | June 2016