February 2024 - 12

TECHNICALLY SPEAKING | BY ERIK RUNKLE
LED lighting: A 2024 update
Light-emitting diodes (LEDs) have become the " go to "
fixture type for most horticultural lighting applications.
Growers are replacing high-pressure sodium (HPS) with
LEDs, often delivering a higher intensity than before.
In addition, new supplemental lighting installations are
usually with LEDs.
There are several reasons for the widespread adoption
of LEDs, most notably the technological advances and
increased grower appreciation for how lighting can
improve crop quality, decrease production time, or both.
LEDs are much more complex than conventional fixtures
because they vary widely in light output (intensity and
spectrum), efficacy (electrical efficiency), beam angle,
cost, ease of installation, etc.
Before delving into some performance characteristics
of LEDs, we need to ensure that fixtures have been
designed to tolerate growing conditions (for example,
high humidity) and meet benchmark standards specific
to horticulture. To help accomplish this, growers are
advised to consider LED products that are on the
Horticultural Lighting Qualified Product list by the
DesignLight Consortium (DLC). Visit designlights.org for
more information.
Three of the major ways to characterize an LED fixture
are light output, light spectrum and efficacy. All three are
based on photons within the photosynthetically active
waveband (PAR; 400-700 nm). There are compelling
reasons to also consider far-red light, which extends PAR
(ePAR) to 750 or 800 nm.
Light output refers to the number of photons (in
micromoles, or µmol) emitted by a fixture per second(s)
and has a unit of µmol·s-1
. Technically speaking, light
output is the photon flux of the PAR (or ePAR) waveband,
which can only be measured in a testing laboratory. The
light spectrum refers to relative percentages of blue, green,
red and far-red light, and although the peak wavelengths
are also important, they are usually not reported.
Finally, fixture efficacy refers to the photon flux of
a fixture divided by the energy consumed to emit that
quantity of light. Its unit is micromoles per joule, or
µmol·J-1
. Fixture efficacy is usually reported for the PAR
waveband (photosynthetic photon efficacy, or PPE).
Table 1 illustrates the variation in light output (photon
flux), light spectrum (percentage of photons in each
of four wavebands), and efficiency (efficacy) of 15 LED
fixtures on the DLC Horticultural Lighting Qualified
While the
performance
metrics of LEDs are
important, there are
other aspects that
merit consideration
when selecting a
lighting fixture.
12
FEBRUARY 2024 GPNMAG.COM

http://www.designlights.org http://www.GPNMAG.COM

February 2024

Table of Contents for the Digital Edition of February 2024

Editor's Report | Hot and cold
Table of Contents
Forty Under 40 Perspectives | Keeping fields cleaner
Dr. Bugs | Stratiolaelaps scimitus
Technically Speaking | LED lighting: A 2024 update
Plant Health | Healthy crops
Production | Understanding poinsettia heat delay
2024 California Spring Trials | CASTing into spring
Lighting | What's your lighting strategy
Pest Control | It's all about the buzz
Culture Report | DoubleShot series
Product Marketplace
Industry News/Events
Classifieds/Ad Index
February 2024 - Editor's Report | Hot and cold
February 2024 - 2
February 2024 - Table of Contents
February 2024 - 4
February 2024 - 5
February 2024 - Forty Under 40 Perspectives | Keeping fields cleaner
February 2024 - 7
February 2024 - Dr. Bugs | Stratiolaelaps scimitus
February 2024 - 9
February 2024 - 10
February 2024 - 11
February 2024 - Technically Speaking | LED lighting: A 2024 update
February 2024 - 13
February 2024 - Plant Health | Healthy crops
February 2024 - 15
February 2024 - 16
February 2024 - 17
February 2024 - Production | Understanding poinsettia heat delay
February 2024 - 19
February 2024 - 20
February 2024 - 21
February 2024 - 2024 California Spring Trials | CASTing into spring
February 2024 - 23
February 2024 - 24
February 2024 - 25
February 2024 - 26
February 2024 - 27
February 2024 - 28
February 2024 - 29
February 2024 - 30
February 2024 - 31
February 2024 - 32
February 2024 - 33
February 2024 - 34
February 2024 - 35
February 2024 - Lighting | What's your lighting strategy
February 2024 - 37
February 2024 - Pest Control | It's all about the buzz
February 2024 - 39
February 2024 - Culture Report | DoubleShot series
February 2024 - 41
February 2024 - 42
February 2024 - 43
February 2024 - Product Marketplace
February 2024 - 45
February 2024 - 46
February 2024 - 47
February 2024 - Industry News/Events
February 2024 - 49
February 2024 - Classifieds/Ad Index
February 2024 - 51
February 2024 - 52
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https://www.nxtbook.com/greatamericanmediaservices/GPN/new-varieties-digital-guide-2025
https://www.nxtbook.com/greatamericanmediaservices/GPN/september-2024
https://www.nxtbook.com/greatamericanmediaservices/GPN/august-2024
https://www.nxtbook.com/greatamericanmediaservices/GPN/july-2024
https://www.nxtbook.com/greatamericanmediaservices/GPN/june-2024
https://www.nxtbook.com/greatamericanmediaservices/GPN/may-2024
https://www.nxtbook.com/greatamericanmediaservices/GPN/april-2024
https://www.nxtbook.com/greatamericanmediaservices/GPN/march-2024
https://www.nxtbook.com/greatamericanmediaservices/GPN/february-2024
https://www.nxtbook.com/greatamericanmediaservices/GPN/january-2024
https://www.nxtbook.com/greatamericanmediaservices/GPN/2024-guide-to-cannabis-production
https://www.nxtbook.com/greatamericanmediaservices/GPN/november-december-2023
https://www.nxtbook.com/greatamericanmediaservices/GPN/october-2023
https://www.nxtbook.com/greatamericanmediaservices/GPN/new-varieties-digital-guide-2024
https://www.nxtbook.com/greatamericanmediaservices/GPN/september-2023
https://www.nxtbook.com/greatamericanmediaservices/GPN/august-2023
https://www.nxtbook.com/greatamericanmediaservices/GPN/july-2023
https://www.nxtbook.com/greatamericanmediaservices/GPN/big-grower-july-2023
https://www.nxtbook.com/greatamericanmediaservices/GPN/june-2023
https://www.nxtbook.com/greatamericanmediaservices/GPN/may-2023
https://www.nxtbook.com/greatamericanmediaservices/GPN/april-2023
https://www.nxtbook.com/greatamericanmediaservices/GPN/big-grower-april-2023
https://www.nxtbook.com/greatamericanmediaservices/GPN/2023-guide-to-hemp-production
https://www.nxtbook.com/greatamericanmediaservices/GPN/march-2023
https://www.nxtbook.com/greatamericanmediaservices/GPN/february-2023
https://www.nxtbook.com/greatamericanmediaservices/GPN/big-grower-january-2023
https://www.nxtbook.com/greatamericanmediaservices/GPN/january-2023
https://www.nxtbook.com/greatamericanmediaservices/GPN/2023-guide-to-cannabis-production
https://www.nxtbook.com/greatamericanmediaservices/GPN/november-december-2022
https://www.nxtbook.com/greatamericanmediaservices/GPN/big-grower-october-2022
https://www.nxtbook.com/greatamericanmediaservices/GPN/october-2022
https://www.nxtbook.com/greatamericanmediaservices/GPN/gpn-new-varieties-digital-guide-2023
https://www.nxtbook.com/greatamericanmediaservices/GPN/september-2022
https://www.nxtbook.com/greatamericanmediaservices/GPN/august-2022
https://www.nxtbook.com/greatamericanmediaservices/GPN/big-grower-july-2022
https://www.nxtbook.com/greatamericanmediaservices/GPN/july-2022
https://www.nxtbook.com/greatamericanmediaservices/GPN/june-2022
https://www.nxtbook.com/greatamericanmediaservices/GPN/may-2022
https://www.nxtbook.com/greatamericanmediaservices/GPN/big-grower-april-2022
https://www.nxtbook.com/greatamericanmediaservices/GPN/april-2022
https://www.nxtbook.com/greatamericanmediaservices/GPN/march-2022
https://www.nxtbook.com/greatamericanmediaservices/GPN/february-2022
https://www.nxtbook.com/greatamericanmediaservices/GPN/cannabisguide-2022
https://www.nxtbook.com/greatamericanmediaservices/GPN/hempguide-2022
https://www.nxtbook.com/greatamericanmediaservices/GPN/newvarieties-2022
https://www.nxtbook.com/greatamericanmediaservices/GPN/big-grower-january-2022
https://www.nxtbook.com/greatamericanmediaservices/GPN/january-2022
https://www.nxtbook.com/greatamericanmediaservices/GPN/december-2021
https://www.nxtbook.com/greatamericanmediaservices/GPN/big-grower-november-2021
https://www.nxtbook.com/greatamericanmediaservices/GPN/november-2021
https://www.nxtbook.com/greatamericanmediaservices/GPN/october-2021
https://www.nxtbook.com/greatamericanmediaservices/GPN/big-grower-september-2021
https://www.nxtbook.com/greatamericanmediaservices/GPN/september-2021
https://www.nxtbook.com/greatamericanmediaservices/GPN/august-2021
https://www.nxtbook.com/greatamericanmediaservices/GPN/big-grower-july-2021
https://www.nxtbook.com/greatamericanmediaservices/GPN/july-2021
https://www.nxtbook.com/greatamericanmediaservices/GPN/june-2021
https://www.nxtbook.com/greatamericanmediaservices/GPN/may-2021
https://www.nxtbook.com/greatamericanmediaservices/GPN/april-2021
https://www.nxtbook.com/greatamericanmediaservices/GPN/big-grower-march-2021
https://www.nxtbook.com/greatamericanmediaservices/GPN/march-2021
https://www.nxtbook.com/greatamericanmediaservices/GPN/february-2021
https://www.nxtbook.com/greatamericanmediaservices/GPN/cannabisguide-2021
https://www.nxtbook.com/greatamericanmediaservices/GPN/hempguide-2021
https://www.nxtbook.com/greatamericanmediaservices/GPN/newvarieties-2021
https://www.nxtbook.com/greatamericanmediaservices/GPN/big-grower-january-2021
https://www.nxtbook.com/greatamericanmediaservices/GPN/january-2021
https://www.nxtbook.com/greatamericanmediaservices/GPN/december-2020
https://www.nxtbook.com/greatamericanmediaservices/GPN/big-grower-november-2020
https://www.nxtbook.com/greatamericanmediaservices/GPN/november-2020
https://www.nxtbook.com/greatamericanmediaservices/GPN/october-2020
https://www.nxtbook.com/greatamericanmediaservices/GPN/big-grower-september-2020
https://www.nxtbook.com/greatamericanmediaservices/GPN/september-2020
https://www.nxtbook.com/greatamericanmediaservices/GPN/august-2020
https://www.nxtbook.com/greatamericanmediaservices/GPN/big-grower-july-2020
https://www.nxtbook.com/greatamericanmediaservices/GPN/july-2020
https://www.nxtbook.com/greatamericanmediaservices/GPN/june-2020
https://www.nxtbook.com/greatamericanmediaservices/GPN/may-2020
https://www.nxtbook.com/greatamericanmediaservices/GPN/april-2020
https://www.nxtbook.com/greatamericanmediaservices/GPN/californiaspringtrials-2020
https://www.nxtbook.com/greatamericanmediaservices/GPN/big-grower-march-2020
https://www.nxtbook.com/greatamericanmediaservices/GPN/march-2020
https://www.nxtbook.com/greatamericanmediaservices/GPN/february-2020
https://www.nxtbook.com/greatamericanmediaservices/GPN/cannabisguide-2020
https://www.nxtbook.com/greatamericanmediaservices/GPN/hempguide-2020
https://www.nxtbook.com/greatamericanmediaservices/GPN/big-grower-january-2020
https://www.nxtbook.com/greatamericanmediaservices/GPN/january-2020
https://www.nxtbook.com/greatamericanmediaservices/GPN/december-2019
https://www.nxtbook.com/greatamericanmediaservices/GPN/big-grower-november-2019
https://www.nxtbook.com/greatamericanmediaservices/GPN/november-2019
https://www.nxtbook.com/greatamericanmediaservices/GPN/october-2019
https://www.nxtbook.com/greatamericanmediaservices/GPN/big-grower-september-2019
https://www.nxtbook.com/greatamericanmediaservices/GPN/september-2019
https://www.nxtbook.com/greatamericanmediaservices/GPN/august-2019
https://www.nxtbook.com/greatamericanmediaservices/GPN/big-grower-july-2019
https://www.nxtbook.com/greatamericanmediaservices/GPN/july-2019
https://www.nxtbook.com/greatamericanmediaservices/GPN/june-2019
https://www.nxtbook.com/greatamericanmediaservices/GPN/may-2019
https://www.nxtbook.com/greatamericanmediaservices/GPN/april-2019
https://www.nxtbook.com/greatamericanmediaservices/GPN/californiaspringtrials-2019
https://www.nxtbook.com/greatamericanmediaservices/GPN/big-grower-march-2019
https://www.nxtbook.com/greatamericanmediaservices/GPN/march-2019
https://www.nxtbook.com/greatamericanmediaservices/GPN/february-2019
https://www.nxtbook.com/greatamericanmediaservices/GPN/undercontrol-2019
https://www.nxtbook.com/greatamericanmediaservices/GPN/big-grower-january-2019
https://www.nxtbook.com/greatamericanmediaservices/GPN/january-2019
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