EconoLux makes the most technologically advanced and energy efficient induction lighting products in the world. This page provides information on the differences in our technology, as well as information on how induction lamps work in an overview of Induction Lighting technology. For additional information, please visit our
- Introduction to Magnetic Induction Lamps: A brief outline of how Magnetic Induction Lighting (electrodeless lamp) technology works.
- Plant-light Technology Background: A summary of the technology incorporated in our ELPL series of Induction Plant/Grow lights.
- Measuring Grow/Plant-light Output: Why the correct way to measure Grow/Plant-Light output is in PAR and NOT in Lumens.
What Makes Our Products Better?
All EconoLux products are built with high quality parts – we use proprietary extrusions and all metal parts are CNC machined to close tolerances. In some products, we use proprietary blends of domestic (Chinese) and imported (Korean, Japanese, and US) rare-earth phosphors, even though the imported phosphors are more expensive, to maximize light output from our lamps. We have rigid Quality Control procedures at every step of production and our production runs are subject to random sample testing to insure they meet our high quality standards.
Introduction To Magnetic Induction Lamps:
|Thomas Edison is generally credited with the invention of the commercially viable electrical lamp we are familiar with (incandescent bulbs). He was building on work done by early pioneers, particularly Canadian inventors Woodward and Evans (who’s 1874 patents Edison purchased), thus Canadians invented the light bulb, but Edison commercialized it. The conversion of electricity to light was demonstrated in laboratories as early as 1801 by Sir Humphrey Davy who is credited with the invention of the electric arc lamp.|
The most common form of electrical lighting we are almost all familiar with is the incandescent lamp. This consists of an evacuated, or noble gas filled, glass envelope, which generally has two electrodes protruding through the bottom wall of the glass vessel, to bring the electrical current into the interior of the lamp. There is a thin filament, usually made of tungsten wire, suspended between the electrodes. There may also be other wires (non-electrically connected support wires) provided for mechanical support of the filament.
|Other Lamp Types:
There are many other types of lamps ranging from xenon arc lamps used in movie projectors, to metal halide, mercury vapour and sodium types, to fluorescent types, to light emitting diodes [LEDs]. It is beyond the scope of this page to cover all of these types in detail (for more information, see http://en.wikipedia.org/wiki/List_of_light_sources). We will cover fluorescent lamps as the Induction lamps are a modified form of the fluorescent lamp.
| A fluorescent lamp is a type of gas discharge tube where an electrical current excites mercury vapour, in an inert gas, producing UV light, typically at the 253.7nm and 185nm wavelengths. This UV light is then up-converted, by a coating of phosphors on the inside of the glass tube, into visible light.
At each end of the typical fluorescent lamp, there are small tungsten filaments which are usually coated with a blend of metallic salts such as barium, strontium and calcium oxides. The filaments are provided to bring the electric current into the lamp, and the metallic salts are designed to promote the emission of electrons, in order to stimulate the mercury ions in the tube.
Fluorescent lamps are a negative resistance device (as more current flows, the resistance decreases allowing even more current to flow), so the lamps require a ballast to control the current to the lamp. The most common and simple type of ballast is a magnetic or „core and coil“ type ballast. This is a form of current limiting transformer which provides the lamp with the correct current needed for it’s operation.
These ballasts are cheap to manufacture, but inefficient, as they emit heat (wasted energy) – generally between 12% and 17% of the energy consumed by the lamp is wasted in the typical „core & coil“ ballast. Newer types of fluorescent lamps use high frequency electronic ballasts. While these are more costly to manufacture, they are much more energy efficient typically only wasting between 5% and 9% of the energy consumed by the lamp.
Almost all of the light sources currently in use have one thing in common, metal electrodes sealed into the walls of the bulb or tube to bring the electrical current inside the lamp chamber/envelope. Unsurprisingly, the main failure mechanisms in these typical lamps [other than breakage] is:
The dream of lighting inventors has been to produce a lamp with no internal electrodes so as to eliminate these common failure modes. In an electrodeless lamp the envelope [bulb] is completely sealed and thus there is no chance of atmospheric contamination due to seal failure and no electrodes/filaments to wear out over time. On 23 June 1891, Nicholas Tesla was granted US patent 454,622 to cover a very early form of Induction lamp.
In an electrodeless lamp, the main failure mechanisms [other than breakage] are:
So how do you get an electrical current inside the bulb (glass envelope) of a lamp to excite the mercury ions within?
|Magnetic Induction Lamps:|
| Magnetic induction lamps are basically a type of fluorescent lamp with (one or two) electromagnets wrapped around a part of the tube (an external inductor lamp), or inserted inside the lamp (an internal inductor lamp).
Light is produced by an up-conversion process within the tube where UV light generated within the lamp by excited mercury atoms, is up-converted to visible light, by a coating of phosphors on the inside wall of the tube. By adjusting the type and composition of the phosphors in the coating, various colour temperatures (E.G.: Warm White, Cool White, etc.) can be produced.There are two main types of Induction Lamps, External Inductor lamps and Internal inductor lamps:
External Inductor Lamps: In external inductor lamps, high frequency energy, from the electronic ballast, is sent through wires that are wrapped in a coil around the ferrite inductor on the outside of the glass tube, creating a powerful magnet.
The induction coil produces a very strong magnetic field which travels through the glass and excites the mercury atoms in the interior. The mercury atoms are provided by the amalgam (a solid form of mercury).
The excited mercury atoms emit UV light and, just as in a fluorescent tube, the UV light is up-converted to visible light by the phosphor coating on the inside of the tube. The glass walls of the lamp prevent the emission of the UV light as glass blocks UV radiation at the 253.7 nm and 185 nm range.
The induction lamp system can be considered as a type of transformer where the inductor outside the glass envelope is the primary coil, while the mercury atoms in an inert gas-fill within the envelope/tube
|The high frequency magnetic field from the inductor, is coupled to the metallic mercury ions causing their electrons to reach an excited state. When the electrons revert to the ground state, photons of UV light are emitted, which excites the phosphor coating to emit visible light.|
|Internal Inductor Lamps:|
| In an internal inductor lamp, a light bulb shaped glass envelope, which has a test-tube shaped re-entrant central cavity, is coated with phosphors on the interior, evacuated, then filled with an inert gas and a pellet of mercury amalgam. The induction coil is wound around a ferrite shaft which is inserted into the central test-tube like cavity. The inductor is excited by high frequency energy, provided by an external electronic ballast, causing a magnetic field to penetrate the glass and excite the mercury atoms, which emit UV, that is then converted to visible light by the phosphor coating.
The external inductor lamps have the advantage that heat generated by the induction coil assemblies is external to the tube and can be easily dissipated by convention or conduction. The external inductor design lends itself to higher power output lamp designs which can be rectangular or round.
In the internal inductor lamps, the heat generated by the induction coil is emitted inside the lamp body and must be cooled by conduction to a heat-sink at the lamp base, and by radiation through the glass walls.
The internal inductor lamps tend to have a shorter lifespan than the external inductor type lamps, due to their higher operating temperatures.
|The internal inductor type lamps look more like a conventional light bulbs, than the external inductor type lamps, thus they may be more aesthetically pleasing in some applications.|
|Ballasts:|| Magnetic induction lamps require a correctly matched electronic ballast for proper operation (sometimes referred to as a „generator“ since it generates the power for the high frequency magnetic field). The ballast takes the incoming mains AC voltage [or DC voltage in the case of 12 and 24V ballasts] and rectifies it to DC. Solid state circuitry then converts this DC current to a very high frequency which is between 2.65 and 13.6 MHz depending on the lamp design. The high frequency produced by the ballast is fed to the coil wrapped around the ferrite core of the external or internal inductor, to produce the magnetic field.
The ballasts contain control circuitry which regulates the frequency and current to the induction coil to insure stable operation of the lamp. In addition, the ballasts have a circuit which produces a large „start pulse“ at power-up to initially ionize the mercury atoms and thereby start the lamp.
|The advantages of Induction lamps are:
These benefits offer a considerable cost savings of between 35% and 75% in energy and maintenance costs(depending on application) compared to other types of HID lamps which our Magnetic Induction Lamps can replace.
Grow/Plant-light Technology Background:
Agricultural lighting (plant/grow lights) are widely used in greenhouses, grow-ops, and other locations to either replace, or augment, natural sunlight (daylight) in the growing of many different types of crops such as fruit, vegetables, greens, herbs, or flowers. In many cases, the electrical energy needed to operate the plant-lights accounts for a significant amount of the input costs involved in the production of these crops. It is therefore desirable to provide a more energy efficient grow/plant-light for these agricultural applications. However, the more energy efficient solution must also provide the appropriate spectrum of light the plants require, in an economically viable manner.
| The EconoLux Industries ELPL series of Magnetic Induction Plant-lights are the result of over 2 years of painstaking research and development, using technology licensed form InduLux Technologies. For more details on the R&D involved in creating these plant-lights and the technology background, please see our publication „Building a Better Plant-light“ available in our on-line Library.
The ELPL series of Induction Plant/Grow-lights provides high, useful (to plants) Blue and Red light output, a closer match to the PAR curve than other plant-lights – all from an energy saving, long lifespan (80,000~85,000 hour), induction lamp. The use of a proprietary, and trade-secret, high-gain phosphor coating, also allows for three different formulations to suit various agricultural applications.
What Light Do Plants Need?
The spectrum of light typically used by plants lies between 400 nanometres (UVA/deep blue) and 700 nanometres (deep red). This wavelength region is known as Photosynthetically Active Radiation or PAR. In addition, some plant types also make use of UVA, UVB, and Infra Red light at different times in their growth cycle.
|Within that 400~700 manometer (nm) region, various pigments within the plants have peak absorption of differing amounts and at different wavelengths (colours). For example, Beta Carotene has absorption peaks at around 462nm and around 501nm. The various absorption peaks can be averaged into an overall light absorption curve, showing the spectrum of light most plants need. This curve is called the PAR curve. The graph shows the various absorption peaks of the major substances in plants which require light, as well as the peaks of the light needed for the plants to make chlorophyll, as a series of dashed vertical lines, where the height of the line corresponds to the approximate intensity of the peak. The dashed navy blue line (that looks like mountains) is the averaged PAR curve. The Spectrum of Sunlight (red line) is also overlaid for reference.|
Note that the PAR Curve has its peak (100%) in the Blue region, around 440nm, and another, lower, peak in the red region around 675nm. You can also see that the plants use very little of the light in the green to yellow region from 540nm to 580nm. This is why most plants appear green to the human eye, because most of the green light hitting the plant is reflected, while the blue and red light is absorbed by the plants to make nutrients.
Plants make use of the blue portion of the spectrum (even though it is not as abundant in sunlight as the orange/red wavelengths), for the higher energy levels provided by the shorter blue wavelengths. Plants make use of the red portion of the spectrum, even though that has lower energy levels, due to the abundance of orange/red wavelengths available in sunlight. The plants make more use of the blue light as the PAR curve peaks at 440nm (100%), while the red peak at 675nm only reaches 95%, thus, generally speaking, plants prefer to have slightly more blue than red light.
Sunlight does not closely follow the PAR curve, as can be seen from the graph, where the typical spectrum of sunlight at noon (red line) is overlaid with the PAR curve (dashed navy blue line). Note that sunlight provides plenty of blue and red light, but also an abundance of green to yellow light in the 520~580nm range, even though the plants need very little of these wavelengths. This „overabundance“ of certain wavelengths (colours) is not a problem for the plants, as they absorb only as much light in the blue and red wavelengths as they need, and simply ignore the rest.
However, for a grow/plant-light, it is important to produce an output spectrum that fits within the PAR curve (as closely as possible) as any excess light produced, or light produced outside of the PAR curve spectrum is simply wasted light. The ‚wasted‘ light represents energy being used producing that light, which the plants don’t need, thereby reducing the overall energy efficiency of the grow/plant-light.
Thus we can determine, from this data, that for proper plant growth, an artificial light source should produce primarily blue and red light with a spectral intensity curve which matches the PAR curve as closely as possible. However, it is well known that plants, in the germination and vegetative phase of their growth, need more blue (high energy) light, while plants in the flowering/fruiting phase of growth need more red (lower energy) light, thus different types of light output spectra may be needed according to the type of plant being cultivated. Ignoring the green portion of the spectrum, the PAR curve is approximately 57% blue and 43% red.
EconoLux ELPL series of induction plant-lights:
Output Spectrum: The ELPL series of plant-lights provides the closest match to the PAR curve (the spectral curve of plant’s light absorption) possible, within the limits of the technology.
| The ELPL series of plant-lights produce the maximum light output in the blue and red regions of the spectrum where it is most useful to the plants. In addition, the output from the ELPL lamps has a smoother, and broader, spectral output than Metal Halide or High Pressure Sodium lamps. The EconoLux plant-lights produce full-spectrum light output (all colours) unlike many LED lamps that produce no output in the green and yellow portions of the spectrum (plants do need some green and yellow light).
The graph (right) shows the light output spectrum from the ELPL-VG (green line) and ELPL-FL (pink line) models, compared to the PAR curve (navy blue dashed line).
Note that the majority of the light output is in the blue and red regions as the plants make little use of green light. Any light falling above the PAR curve is an „overabundance“ of light and it is simply ignored by the plants unless they can make use of it. The Two different types, VG and FL, have different Blue to Red ratios to suit different plant types.
Useful Light Output: The ELPL series of lamps produce the vast majority of their light output in the blue and yellow to red portions of the spectrum. The green light produced (540~560nm) is a small fraction of the total lamp output, and the plants can utilize about 31% of that green light output (the balance is an ‚overabundance‘ falling above the PAR curve and is ignored by the plants). As a result, the ELPL lamps produce between 93% and 95% of light useful to plant cultivation. Little energy is wasted producing light that the plants cannot use, compared to the useful (to plants) light output of about 75% for HPS lamps, and about 82% for MH lamps.
|Lifespan: Since the ELPL plant-lights is based on Induction Lighting technology, which has no filaments or electrodes to wear out, the lamps offer an exceptionally long lifespan. The ELPL plant growing lamps have a lifespan of 80,000 to 85,000 hours of operation – that’s over 9 years of 24/7 use!
The extended lifespan also saves time and money on the purchase of replacement lamps, and the labour for re-lamping. Typically, an ELPL plant-light can outlast more than 9 Metal Halide (MH) lamps and more than 5 High Pressure Sodium (HPS) lamps!
Low „Heat Signature“: The ELPL lamps operate at temperatures of around 52C (144.8F) on the glass, much lower than the temperatures found in Metal Halide (MH) and High Pressure Sodium (HPS) Lamps (typically 900~1,100C (1,652~2,012F) for MH and HPS lamps). Unlike most LED plant-lights (which also operate at lower temperatures than MH and HPS lamps), they do not incorporate fans that may need cleaning and replacement during the lifetime of the LED fixture. The ELPL series relies on passive cooling (conduction and convention) thus little, or no, heat extraction/ventilation equipment is needed, saving on the cost of the energy usually required to operate that equipment. The low operating temperatures also provide further benefits such as:
- Improved moisture control and a reduced need for watering and nutrients due to less evaporation;
- Significantly reduced heat damage to sensitive shoots and flower buds at the tops of the plants;
- Improved light ‚intensity‘ as the ELPL series lamps can be mounted closer to the plants (see diagram). Since light falls off with the square of the distance, the closer the plant-lights can be mounted to the vegetation (without damaging it), the more light can be delivered to the plants.
|Lumen Maintenance: As any artificial light sources ages, it’s light output decreases. This „lumen depreciation“ can be plotted as a lumen maintenance curve which shows how well the light source maintains its output levels over its lifespan.
In the case of Metal Halide (MH) and High Pressure Sodium (HPS) plant-lights, they have shorter lifespan and steep lumen depreciation, necessitating frequent lamp replacements (see chart). While LED plant-lights last longer (50,000 ~ 55,000 hours) they also have steeper lumen depreciation than the ELPL series. The ELPL plant-lights have excellent lumen maintenance, producing higher levels of light output for a longer time, that competing plant-light technologies.
Significant Energy Savings: When the ELPL series of plant-lights replaces MH and HPS lamps, they can provide energy savings of between 74% and 31% depending on the technology replaced (not including any additional saving on reduced ventilation/cooling costs). For example, a 600W HPS lamp can be replaced with a 300W ELPL lamp saving 56.6% in energy costs, also saving the cost of 5 replacement HPS lamps, and the cost of the re-lamping labour. In many cases, higher power LED plant-lights can be replaced with slightly lower wattage ELPL lamps due to the much broader spectrum of light output from the ELPL lamps, saving 25% to 40% in energy costs.
A plant-light substitution table, providing guidelines for replacing MH and HPS lamps, along with energy savings and re-lamping savings, is provided in the Appendix section of the „Building A Better Plant-light“ publication in our Library.
Advanced Coating: The ELPL series of induction plant-lights uses a proprietary, and trade-secret, blend of domestically produced, and imported, high-gain phosphors to maximize light output. Our self-developed phosphor technology also allows us to offer different coatings to suit different applications such as growing vegetative or flowering plants. We are the only induction plant-light manufacturer who can provide these coatings.
|Two Different types: The ELPL series of plant lights are available in two different coating types to suit different agricultural applications.
The graph shows the comparison of the two types, where the maximum output peak of the lamps is shown at 100%, while the PAR curve (plants light absorption curve – shown as a dashed navy blue line) has been normalised to 60% of relative spectral response.
The ELPL-VG type has more blue than red for growing vegetative plants, while the ELPL-FL type has more red than blue for growing flowering plants. For more detail on the spectral output curves of the ELPL series lamps, please request a copy of our catalogues or test reports.
- ELPL-VG: Designed to growing vegetative (non-flowering) plants or for use in sprouting/germination/cloning areas where early plant growth requires additional blue light. It offers a balance of 59% Blue to 32% Red light, and an output of 96.5% light useful to plants (excess green light has been deducted) – a Blue to Red ratio of 5.9:3.2.
- ELPL-FL: Designed for growing fruiting/flowering plants that need additional red light output. It offers a balance of 41% Blue to 55% Red light, and an output of 96.5% light useful to plants (excess green light has been deducted) – a Blue to Red ratio of 4.1:5.5.
|Integrated Thermal Management: The ELPL lamps are designed with custom inductor heat-sinks that have almost twice the mass and surface area, compared to industry averages. This helps to more rapidly dissipate the lamp heat through conduction and convention – lower operating temperatures increase lamp lifespan. They are also laser engraved to allow for rapid identification of lamp type/model in the field.
In addition, the ELPL series lamps come pre-mounted to a custom, extruded, thermal bridge (heat sink) to provide additional heat dissipation. The Thermal bridge is provided with slotted holes at either end (and other threaded holes) making it simple to mount the lamp.
Operational Flexibility: The ELPL series are driven by your choice of electronic ballasts with universal voltage input of 110VAC ~ 277VAC, 50/60 Hz or 200VAC ~ 350VAC, 50/60 HZ allowing them to be used in many different countries. The electronic ballast also compensate for minor voltage fluctuations keeping the lamp output stable. The ballasts have a high power factor of between 0.99 and 0.95 (depending on model – only between 1% and 5% of the total energy is wasted in the ballast) for enhanced energy savings.
Green Technology: The ELPL series of plant lights reduces energy consumption in agricultural applications, thereby also reducing CO2 production from power generation. The ELPL series uses solid mercury amalgam which is more environmentally friendly than the liquid mercury used in HPS and MH lamps. In addition, over the lifespan of the ELPL lamps, they use 8 times less mercury than HPS lamps, and 24 times less mercury than MH lamps!
Product Cost: The ELPL series of induction plant-lights are more costly than standard induction lamps, due to the high quality of the components, precision manufacturing, CNC machined parts, the use of imported phosphors, and the integrated thermal management provided. However, they are still cost competitive with brand-name MH and HPS agricultural lamps driven by electronic ballasts, and with most models of LED plant-lights.
The graphs below provide a comparison between the spectral output of the ELPL series of plant/grow lights, and popular Metal Halide, High Pressure Sodium, and dual/quad band LED plant/grow lights, as well as some induction „plant-lights“ currently available on the market; compared to the PAR curve:
| The graph (left) shows the spectrum of the ELPL-VG Vegetative type lamps (green line) compared with with a typical „neutral“ Metal Halide (MH – blue line) lamp. Metal Halide lamps are generally used for germination, sprouting and cloning – the vegetative phase of plant growing.
Note that the output of the MH lamp is a series of ’spikes‘ and that it is producing the majority of it’s light output in the green to yellow range, where the plants can only make limited use of that light. The MH lamp has reasonable blue output, but little to no red output; while the VG lamp provides a very wide and smooth spectrum of blue light, as well as far more red light than the MH lamp as even vegetative phase plants require some red light.The graph (left) shows the spectrum of the ELPL-FL Flowering type lamps (pink line) compared with with a „Super high output“ High Pressure Sodium (HPS – orange line) lamp. HPS lams are generally used for the flowering/fruiting phase of plant growing.
Note that the output of the HPS lamp is a series of ’spikes‘ and that it is producing the majority of it’s light output in the green to yellow range, where the plants can only make limited use of that light. The HPS lamp has very low blue output, and not very much red output; while the FL lamp provides a very wide and smooth spectrum of blue light, as well as far more red light than the HPS lamp with little wasted light in the Green/yellow portion of the spectrum.
| Neither the MH or HPS lamps have a good match to the PAR curve due to their spiky output and overall lack of red. On the other hand, the ELPL plant/grow light lights have a much closer match to the PAR curve. They produce a broad spectrum of blue light, they produce a low level of light in the green to yellow range, and they also produce a broad spectrum of plentiful red light; thus they are ‚full spectrum‘ lights, producing more light output that the plants can use (95% of the total ELPL light output produced), compared to the MH (about 83%) and HPS (about 75%) plant/grow lights.
|The graph (right) compares the ELPL-FL Flowering type growing lamps (pink line), with the typical „dual band“ (blue line) and „quad-band“ (purple line) types of LED plant/grow lights. The „dual-band“ types use only two kinds of LEDs, one kind of blue and one kind of red. As a result, they produce two very narrow spikes in the blue and red, and thus are not ‚full spectrum‘ grow lights. The more costly „quad-band“ types use two different kinds of blue LEDs and two different kinds of red LEDs to broaden the output, which is still two (wider) spikes and not ‚full spectrum‘. The LED lamps do not have a close match to the PAR curve producing a limited spectrum of blue and red light, and little to no green or yellow light (plants do need some green and yellow light).|
| The ELPL-GP plant/grow light lights have a much closer match to the PAR curve (dashed navy blue line). They produce a broad spectrum of blue light, they also produce light in the green to yellow range, and they also produce a broad spectrum of red light, thus they are ‚full spectrum‘ lights, producing more light that the plants can use, compared to the LED lights.
| There are some induction lamp vendors offering „plant-lights“. These are generally modified white-light versions, or the „bi-spectrum“ type where one half of the tube is coated with Blue phosphors and the other half is coated with „red“ phosphors. Neither type produces a very good spectrum for plant growth.
The graph on the left shows a comparison of the ELPL-FL induction grow lamp (pink line) with an I-G induction plant-light (modified white-light type – green line), and an RBS induction plant-light („bi-spectrum“ type – orange line). These are compared to the PAR curve.
| From the graph (above) we see that the ELPL-FL induction plant-light, and the other induction plant-lights, have somewhat similar smooth output curves in the blue region, although both the example I-G and RBS induction plant growing lamps have weak blue output, compared to the ELPL lamp. In the green region (495nm~570nm) all of the induction lamps produce some light, but the I-G lamp is producing slightly more green light. Both the I-G and RBS lamps are producing „red“ light that is actually in the orange region (around 610nm), and is not close to the plant absorption lines in the red region. Further, the balance of the amount of blue light to „red“ light is heavily tilted towards the „red“ output in these lamps. The ELPL lamp is producing a broad spectrum of red light with good coverage of the plant absorption lines in the red part of the spectrum, especial the critical chlorophyll synthesis absorption peak.
None of the other induction plant-lights presently on the market offer different spectrums for cultivating different types of plants. The ELPL series offers two different types of lamps (VG and FL), allowing the user to choose the spectral curve best suited to the type of crops they are growing, Vegetative of Flowering.
The graph below compares the Blue to Red output ratios and the percentage of light output useful to plants of High Intensity Discharge lamps (metal Halide and High pressure Sodium), with the output of the EconoLux ELPL series of energy saving plant/grow lights:
The ELPL-REDshiftTM system uses a combination of two of our proprietary (and trade-secret) ELPL series plant growing lights and is available in two versions, one for vegetative plants (REDshift-VG) and one for flowering plants (REDshift-FL). The REDshiftTM system gives the grower the benefit of controlling the blue to red balance of the light delivered to the plants at the flick of a switch.
|Measuring Grow/Plant-Light Output:|
Almost all manufacturers of plant growing lights (MH, HPS, LED, T5HO and Induction), quote the output of their lamps in Lumens. This is a measure of the amount of Lumens a lamp is producing (according to the 1951 CEI Photopic Luminosity curve). However, the CIE* Luminosity curve used in the Lumens measurement, applies to light sources designed to produce light for human vision, not to agricultural/plant lights! Thus the Lumens figure, when applied to grow/plant-lights, can be very misleading and/or deceptive.
When measuring plant-light output, the correct unit of measurement for proper evaluation, is to measure in „PAR“ using a PAR meter (quantum flux meter). PAR stands for Photosynthetically Active Radiation – a measurement of light the would be used by plants for photosynthesis, the process that powers plant growth. Measuring in PAR gives a much more accurate comparison of the light energy produced by a grow/plant-light lamp, and the amount of light useful to the plants which the plant/grow lamp is producing. EconoLux is the only induction plant-light manufacturer providing lamp output values in PAR.
The instrument used to obtain the spectral output graphs of the ELPL plant-lights (and other plant-light technologies tested), is an „integrating sphere“. Our (EverFine brand) integrating sphere instrument is a two meter in diameter sphere, with a special diffused white coating on the interior, which integrates the light output of the lamp under test, delivering it to the sensors.
Light sources to be tested are placed/hung in the centre of the sphere, connected to the power source provided by the integrating sphere, and allowed to warm up before the test is run. The integrating sphere collects the diffuse light from the light source (lamp) under test, and can then produce readings of the spectrum, lumen output, ratio of blue, green, and red light emitted, etc. It also provides the electrical characteristics (such as voltage, watts consumed, power factor, etc.) by reading the integrated power analyser that is supplying the power to the light source in the integrating sphere.
| While this instrument is calibrated to the CIE curves for visible light when making total flux (Lumens) and Lumens/Watt readings, it is still very useful for providing the spectral distribution of the plant-lights, Kelvin, and the electrical characteristics of the lamps.Remember: Lumens are for Humans – PARs are for Plants
* CIE = International Commission on Illumination (usually abbreviated CIE for its French name, Commission Internationale de l’eclairage); IES = Illumination Engineering Society.
Trial 1: We arranged to have a university researcher to perform a trial growing run using a 250W sample of our ELPL plant growing lamp, where our lamp was compared with a 650W LED plant-light and a 1,000W High Pressure Sodium (HPS) plant-light.
| The ELPL-GP pant-light was mounted in a housing with a reflector, and used to grow 6 different plant types – Basil, Chard, Lettuce, Cucumber, Tomatoes and Peppers. The plants were grown in cycles for 90 days (except the Chard under the HPS lamp which died before the tests were over), and then each plant type was subjected to a battery of tests.
Using the data collected for each type of plant grown, and averaging it, we created the chart on the left. The chart shows the averaged results of the 6 different types of plants grown, with the Brix (nutrient content) value, the plants PH value, the plant weight in grams, the root weight in grams, the plant height in centimetres, and finally the power consumption of the grow-lights (with the ballast overhead included).
| The vertical cyan bars represent the averages for the LED plant-light, the orange bars are the averages for the HPS lamp, and the pink bars show the averages for the EconoLux ELPL induction plant-light lamp.
As can be seen from the chart above, the plants grown under the ELPL induction plant-light had the highest average Brix (nutrient content) value, while consuming the least electrical power. In almost all of the other categories, the ELPL induction plant-light produced comparable, or better, results than the LED and/or HPS lamps, except for root weight which was lower than average. Since some of the plants grown were vegetative types, it would have been better to have used the ELPL-VG type of lamp for growing those plants (they need additional blue for good root formation), which would have increased the average root weight for plants grown under the ELPL lamps.Trial 2: We arranged with a greenhouse to test a 300W ELPL-VG lamp in their germination area where it replaced a 600W Metal Halide lamp, saving over 56% in energy costs! The photo below shows some samples plants after 2 weeks of growth. The top images (with the blue square around them) are the plants grown under the Metal Halide lamp, after 2 weeks of growth. The bottom images are the same types of plants grown under the ELPL-VG lamp after 2 weeks of growth – temperatures and watering schedule were the same for both sets of plants. As you can see, the plants grown under the ELPL lamp are larger, healthier and growing better, while saving the greenhouse on energy and re-lamping costs.Trial 3: We presently have an ongoing growing trial with a licensed Medical Cannabis grower using our ELPL REDshift-VG in the „Veg room“ and our REDshift-FL in the „Flowering room“ of his grow-op. Preliminary results are favourable but we have no hard data as yet. However, the grower has reported that his ventilation and air-conditioning usage has decreased considerably since installing our lamps.
| Considering the Green Technology EconoLux ELPL series plant-lightsclose match to the PAR curve, smooth full-spectrum output, theirextended lifespan, excellent lumen maintenance characteristics, low heat signature, energy and maintenance savings.
When used to replace other plant-light technologies, the ELPL series of plant growing lamps offers an excellent value for money with high Return On Investment (ROI), and short payback periods!
|References: „Photosynthetically Active Radiation (PAR) is defined as the photons of radiation in the 400 to 700 nm waveband. PAR is a general term that can describe either the photosynthetic photon flux density (PPF), or the photosynthetic irradiance (PI).“ – Plant Physiology: Manipulating Plant Growth with Solar Radiation – Dennis Decoteau, Ph.D., Department of Horticulture, The Pennsylvania State University.
 „The energy contained in light is absorbed in the chlorophyll of plants. Not all wavelengths of light are utilized with equal efficiency. Looking at a chlorophyll/light absorption curve (PAR Curve), one can deduce that red and blue light are more effective than green. This is logical. Plants do not use all of the green light. They reflect it. This is why plants appear green.“ – Wayne Vandre – Fluorescent Lights For Plant Growth- University Of Alaska, Fairbanks.
 „Life Under The Sun“ by Peter A. Ensminger, Yale University Press (March 1, 2001)
 From Manufacturers specifications and tests in our Integrating Sphere
For more detailed and in-depth information, please visit our on-line Library where there are a number of papers on the technology, applications and case studies available as PDF files.
You can Contact us at the factory for any information you need on our products that is not already available from the publications in our Library section, or you can request a catalogue from our Catalogues Library. In most cases, we will refer you to your nearest Dealer/Distributor who will provide assistance in your local language and time zone.