Thursday, May 5, 2011

LED Grow Lights

LED lights for plants growing
Grow lights are usually used for indoor gardening, plant propagation and food production, including indoor hydroponics and aquatic plants. Although most grow lights are used on an industrial level, some small-scale/domestic usage of these lamps has also been found.

According to the inverse square law, the intensity of light radiating from a point source (in this case a bulb) that reaches a surface is inversely proportional to the square of the surface's distance from the source. So if an object is twice as far away, it receives only 1/4 the light. This is a serious hurdle for indoor growers, and many techniques are employed to use light as efficiently as possible. Reflectors are thus often used in the lamps to maximize light efficiency. Plants or lights are moved as close together as possible so that they receive equal lighting and that all light coming from the lamps wind up on the plants (rather than partly besides it). Often, the distance between lamp and plant is in the range of 24 inches (with incandescent lamps), up to 4 inches (with other lamps as compact, large and high-output fluorescent lamps). Many home gardeners cover the walls of their grow-room with a reflective material, or alternatively, white paint to maximize efficiency.

Light requirements of plants
To determine the appropriate lighting (and the lamp to be best used), the specific needs of the plant need to be determined. To arrange optimum lighting, the lighting present in the plant's natural environment need to be imitated. Of course, the bigger the plant gets the more light it requires; if there is not enough light, a plant will not grow, regardless of other conditions.

For example vegetables grow best in full sunlight and high light levels are needed to grow vegetables well indoors (fluorescent lamps, or MH-lamps are thus preferred). Foliage plants (e.g. Philodendron) grow in full shade and can grow normally with relatively little artificial light (thus for the latter, regular incandescents may already suffice).

In addition, plants also require both dark and light ("photo"-) periods. Therefore, lights may to be timed to turn them on and off at set times. The optimum photo/dark period depends on the species and variety of plant (some prefer long days and short nights and others prefer the opposite, or something in between).

For indoor gardening, one of the most important topics is light density, measured in lux. Light density is the amount of light incident on a surface. One lux equals one lumen (unit) of light falling on an area of one square meter. A brightly lit office would be illuminated at about 400 lux. In Imperial (pounds-feet) terms, a foot-candle, or the intensity of a standard candle on an area of 1 square foot, is about 10.76 lux. In professional farming PAR watt or microeinstein per squaremeter
second is used instead of lux, because lux is optimized for human vision, not for photosynthesis, and can be very misleading in case of non-white lightsources, like the purplish-looking LED growlights.

LED grow lamps
LED panel light source used in an experiment on plant growth by NASA. Pictured plant is a potato plant.Recent advancements in LEDs have allowed for the production of relatively cheap, bright, and long lasting grow lights that emit only the wavelengths of light corresponding to chlorophyll's absorption peaks. These lights are attractive to indoor growers since they do not consume as much power, do not require ballasts, and produce a fraction of the heat of HID lamps. Since there is a significant reduction in heat, time can be extended between watering cycles because the plants transpire less under LED grow lights. A caution is warned to those growing with LEDs not to over water the plants.

There are four chlorophyll absorption peaks and LED grow lights use four different types of LEDs to hit all four peaks (two red and two blue).Early LED grow lamps used hundreds of fractional watt LEDs and were not effective replacements for HID lamps. Newer advanced LED grow lamps use automotive grade 2-3 watt LEDs and have shown similar results to HID lamps.

For the plant photosynthesis, The best lighting wave is 400nm~700nm. Usually, Different color LED is a special wave light, royal blue 440nm~460nm, blue 460~490nm, cyan 490~520nm, green 520~550nm, red 620~645nm, orange 613~620nm, amber 585~597nm. The scientist find that the blue 400~520nm light, Red light 610~720nm, Orange 613~620nm are best rays for plant photosynthesis. LED grow lamp provides the right rays. Spectrum-tailored grow light is plant specific and more efficient than incandescent. The Plant LED grow lamp uses LEDs to generate the specific colors of light that plants use most efficiently for vigorous growth and health. Increase florescence time much more. For example, For the flower in vase indoor, The florescence increased to 20 days is not impossible. In addition, the lamp uses significantly less energy and gives off much less waste heat than broad-spectrum devices based on incandescent, fluorescent, or metallic-vapor technology. Especially for office plant and stove plant. You just need to buy our red LED light bulbs and blue LED light bulbs as mixed color lighting system.


Anonymous said...

led grow light bulbs very good blog topic dear about key chain of led i think all the people want to have good key chains with him and they want charming and nice looking chains also so keep it up dear for more

Green Lamp said...

Thanks for taking the time to post this article; this blog is really interested..! UFO Led Grow Lights

Anonymous said...

This post gives best ideas to know how much Plant grow lights a plant needs. It's valuable information for commercial growers as they often have wide variety of plants and they need to take broad approach to lighting.. Keep it up

Anonymous said...

Is this still relevant for today? Or have things changed? What I'm curious about is how this will carry out, like what will the trend be for this type of stuff?

Herry jonson said...

We were among the first companies in the world to offer direct to consumer Best LED Grow Lights. We design our lighting, conduct real-time research in live grow environments that are under our control, and most importantly we fully understand what it takes to grow premium quality flowering plants under LED.

Moorthi Radhakrishnan said...

I’m really impressed with your article, such great & useful knowledge you mentioned here
Led Grow Light

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