Fluorescent Lamps
Fluorescent lights (Fig. 2) are often used as commercial plant grow lights when greater energy
efficiency is required. These white lights use much less electricity than HPS lights, while less waste heat
means lower cooling costs. At the same time the usable light output of fluorescent tubes is much lower
than the output of HPS lights. To compensate for this the lights are typically mounted on movable frames
hung on chains or wires, positioned just inches above the tops of the plants. As the plants grow taller the
lights are manually raised, maintaining the optimal distance between the lights and plants.
Fluorescent lights (Fig. 2) are often used as commercial plant grow lights when greater energy
efficiency is required. These white lights use much less electricity than HPS lights, while less waste heat
means lower cooling costs. At the same time the usable light output of fluorescent tubes is much lower
than the output of HPS lights. To compensate for this the lights are typically mounted on movable frames
hung on chains or wires, positioned just inches above the tops of the plants. As the plants grow taller the
lights are manually raised, maintaining the optimal distance between the lights and plants.
| LED Plant Light Bar Commercial Growing Analysis and Recommendations |
| HPS Grow Light Conversion |
Introduction
Technology Comparison is a brief comparison of the light delivery techniques used with three grow lighting technologies: mercury vapor lamps such as
HPS lamps, fluorescent tubes, and an LED grow light.
Technology Comparison is a brief comparison of the light delivery techniques used with three grow lighting technologies: mercury vapor lamps such as
HPS lamps, fluorescent tubes, and an LED grow light.
Technology Comparison:
| Correct Positioning of LED Plant Light Bar |
Professional growers face a number of challenges when growing plants under artificial light sources. These include, but are not limited to, greenhouse
climate control, designing an array of lights adequate for the lighting needs of each plot, and proper positioning of the lights above plants. The following
describes and discusses the light fixture positioning requirements for traditional white light based grow lights and Light Emitting Diode (LED) based grow
lights.
climate control, designing an array of lights adequate for the lighting needs of each plot, and proper positioning of the lights above plants. The following
describes and discusses the light fixture positioning requirements for traditional white light based grow lights and Light Emitting Diode (LED) based grow
lights.
Mercury Vapor Lamps
The white light bulb most commonly used as an artificial source of plant grow lighting is the High Pressure Sodium
(HPS) lamp (Fig.1). In these lamps an electric arc is produced through a metallic vapor mix, which is contained within a
glass envelope. The electric arc acts as a high-intensity point light source. To maximize efficiency, reflectors of various
shapes are used to redirect the light emitted from the upper side of the HPS lamp down onto the plants being illuminated. The resulting light pattern is
very broad and roughly conical in shape. Arc lamps generate a great deal of heat as well as white light, and are typically
mounted five to ten feet above the planting area to minimize potential heat damage while maximizing the grow area.
The white light bulb most commonly used as an artificial source of plant grow lighting is the High Pressure Sodium
(HPS) lamp (Fig.1). In these lamps an electric arc is produced through a metallic vapor mix, which is contained within a
glass envelope. The electric arc acts as a high-intensity point light source. To maximize efficiency, reflectors of various
shapes are used to redirect the light emitted from the upper side of the HPS lamp down onto the plants being illuminated. The resulting light pattern is
very broad and roughly conical in shape. Arc lamps generate a great deal of heat as well as white light, and are typically
mounted five to ten feet above the planting area to minimize potential heat damage while maximizing the grow area.
Light Emitting Diode (LED) Lamps
Light emitting diodes (LEDs) (Fig. 3) have an internal reflector beneath the diode chip, an epoxy
body which acts as a light tube, and an integral lens. These components determine the angle of the light
beam, emitted as a cone, by each individual LED. As relatively low intensity light devices producing a
small cone of light, LEDs are typically grouped in arrays to both improve the intensity of the light source
and to broaden the light cone.
The light intensity of all three of these light sources, HPS, fluorescent, and LED, follow the inverse
square law i.e. the light intensity decreases as the square of the distance from the light. For very high
intensity lighting such as HPS this means one can achieve adequate light levels for growing plants at
distances up to ten feet from the plant tops.
For lights of lower intensity, such as fluorescent and LED lighting, the light levels become too low to
support healthy plant growth if the lights are mounted too far from the top of the plants. Because of this,
it is not desirable to mount either fluorescent or LED grow lights in a fixed position above a growing area. To achieve light levels that are optimal for
supporting plant growth it is ideal to have both fluorescent and the LED plant light to be mounted on movable frames which are raised at the plants
beneath them grow taller. The movable frame also facilitates raising the lights out of the way when tending the plants. Each light array is typically
mounted to a base which is suspended by cables and moved through the use of a small hand winch.
Light emitting diodes (LEDs) (Fig. 3) have an internal reflector beneath the diode chip, an epoxy
body which acts as a light tube, and an integral lens. These components determine the angle of the light
beam, emitted as a cone, by each individual LED. As relatively low intensity light devices producing a
small cone of light, LEDs are typically grouped in arrays to both improve the intensity of the light source
and to broaden the light cone.
The light intensity of all three of these light sources, HPS, fluorescent, and LED, follow the inverse
square law i.e. the light intensity decreases as the square of the distance from the light. For very high
intensity lighting such as HPS this means one can achieve adequate light levels for growing plants at
distances up to ten feet from the plant tops.
For lights of lower intensity, such as fluorescent and LED lighting, the light levels become too low to
support healthy plant growth if the lights are mounted too far from the top of the plants. Because of this,
it is not desirable to mount either fluorescent or LED grow lights in a fixed position above a growing area. To achieve light levels that are optimal for
supporting plant growth it is ideal to have both fluorescent and the LED plant light to be mounted on movable frames which are raised at the plants
beneath them grow taller. The movable frame also facilitates raising the lights out of the way when tending the plants. Each light array is typically
mounted to a base which is suspended by cables and moved through the use of a small hand winch.
A New Paradigm
Growing plants under solid-state lighting (LED) arrays will require a shift in traditional paradigms. LED plant grow lights emit only wavelengths of light
that target healthy, robust growth. Missing is the blinding white light and searing IR wavelength heat typically associated with traditional white light
sources. LED grow lights look different and they work differently.
For researchers, this will require a change in the methods used to collect light emission data. LED grow lights emit wavelengths of light which are
typically 100% absorbed by healthy plants. This is in contrast to the traditional white light bulb which emits the majority of it's light wavelengths which
are either harmful to both plants and humans such as IR and UV, or in white light components in the yellow and green wavelengths which are typically of
little value to most plants.
Researchers have long been accustomed to measuring the total light emitted by a bulb, rather than the effective light emitted. This trend will need to
change since the aggregate light emitted by LED light arrays, without the waste of UV, IR, and white light components, is not directly comparable to
traditional white light measurements and resulting expectations. Another major difference in solid-state lighting (LED) relates to the sizing of light
sources based on the power consumption, typically stated as watts. Until modern color rendering methods, a light was a light and the only difference
was how much power it consumed. The greater the power consumption, the greater the amount of white light emitted. LED lights, being solid-state
devices, have a typically narrow power consumption window, usually only a few milliamps of power. The total amount of light is typically a function of the
number of individual LEDs in an array and the beam angle of the individual LED design.
Growing plants under solid-state lighting (LED) arrays will require a shift in traditional paradigms. LED plant grow lights emit only wavelengths of light
that target healthy, robust growth. Missing is the blinding white light and searing IR wavelength heat typically associated with traditional white light
sources. LED grow lights look different and they work differently.
For researchers, this will require a change in the methods used to collect light emission data. LED grow lights emit wavelengths of light which are
typically 100% absorbed by healthy plants. This is in contrast to the traditional white light bulb which emits the majority of it's light wavelengths which
are either harmful to both plants and humans such as IR and UV, or in white light components in the yellow and green wavelengths which are typically of
little value to most plants.
Researchers have long been accustomed to measuring the total light emitted by a bulb, rather than the effective light emitted. This trend will need to
change since the aggregate light emitted by LED light arrays, without the waste of UV, IR, and white light components, is not directly comparable to
traditional white light measurements and resulting expectations. Another major difference in solid-state lighting (LED) relates to the sizing of light
sources based on the power consumption, typically stated as watts. Until modern color rendering methods, a light was a light and the only difference
was how much power it consumed. The greater the power consumption, the greater the amount of white light emitted. LED lights, being solid-state
devices, have a typically narrow power consumption window, usually only a few milliamps of power. The total amount of light is typically a function of the
number of individual LEDs in an array and the beam angle of the individual LED design.
Technology Summary
Today's plant grow lights are merely an adaptation of yesterday's warehouse and factory illumination bulbs. Never originally designed to do more
than help a person find their way in the dark, the physics of these bulbs are severely limited. In reality, plant grow light bulbs are manufactured as
imperfect illumination devices. That is, chemicals and gases are added to the bulb to slightly increase light wavelengths that are beneficial to plant
growth which at the same time render the bulb unacceptable for general lighting.
LED lighting arrays are designed specifically for the application. Light absorption in plants occurs over a wide range of wavelengths, but in greatly
varying degrees. LED arrays can target wavelengths that have high absorption rates for extremely efficient operation.
In summary, today's movement away from traditional white light sources is well justified. The benefits of reduced energy consumption, both from
powering white light sources and heat removal, more than pay for the conversion to solid-state lighting (LED). Add to this the increased concern over
white light pollution in many communities and it's easy to see why the time is right to move to targeted wavelength plant grow lights.
Today's plant grow lights are merely an adaptation of yesterday's warehouse and factory illumination bulbs. Never originally designed to do more
than help a person find their way in the dark, the physics of these bulbs are severely limited. In reality, plant grow light bulbs are manufactured as
imperfect illumination devices. That is, chemicals and gases are added to the bulb to slightly increase light wavelengths that are beneficial to plant
growth which at the same time render the bulb unacceptable for general lighting.
LED lighting arrays are designed specifically for the application. Light absorption in plants occurs over a wide range of wavelengths, but in greatly
varying degrees. LED arrays can target wavelengths that have high absorption rates for extremely efficient operation.
In summary, today's movement away from traditional white light sources is well justified. The benefits of reduced energy consumption, both from
powering white light sources and heat removal, more than pay for the conversion to solid-state lighting (LED). Add to this the increased concern over
white light pollution in many communities and it's easy to see why the time is right to move to targeted wavelength plant grow lights.
Comparison to Legacy General Electric Lucalox 1,000 watt HPS Grow Light System
Direct comparisons between two different types of plant grow lighting systems is sometimes difficult and often not well understood. Based on
documents obtained from General Electric and research, we can provide the following specifications for the 1,000-watt Lucalox grow lamp:
Direct comparisons between two different types of plant grow lighting systems is sometimes difficult and often not well understood. Based on
documents obtained from General Electric and research, we can provide the following specifications for the 1,000-watt Lucalox grow lamp:
Suggestions for Additional Enhancements of Grow Chamber
Vertically Stacked Planting Beds
Using LEDs as a plant growing light source greatly reduces the distance between the planting bed and the lights, allowing more efficient use of the
available growing chamber volume. Using PlantLEDs as the plant light source, it is possible to employ up to three or more vertical layers of planting
beds in the area now being used by each single planting bed. This would effectively at least triple the biomass production of the growth chamber.
Using LEDs as a plant growing light source greatly reduces the distance between the planting bed and the lights, allowing more efficient use of the
available growing chamber volume. Using PlantLEDs as the plant light source, it is possible to employ up to three or more vertical layers of planting
beds in the area now being used by each single planting bed. This would effectively at least triple the biomass production of the growth chamber.
Using Solar Panels to Operate PlantLED
The low power requirement of LED grow lights simplifies the conversion to a solar energy system. A solar "photovoltaic" panel/battery system of
450 watts @24vdc will supply ample power for almost 50 LGM5s allowing the lights to operate continuously, 24 hours per day. A solar system of this
size has an estimated cost of under $3,000 for 100% power grid independence while maximizing grow chamber utilization.
The low power requirement of LED grow lights simplifies the conversion to a solar energy system. A solar "photovoltaic" panel/battery system of
450 watts @24vdc will supply ample power for almost 50 LGM5s allowing the lights to operate continuously, 24 hours per day. A solar system of this
size has an estimated cost of under $3,000 for 100% power grid independence while maximizing grow chamber utilization.
| Toll Free in the US and Canada 1-866-414-7244 Fax 541-610-1973 International Inquiries to 1-541-504-6360 Email LED Grow Master Global, LLC at info@led-grow-master.com |