A chip on board LED lights, commonly referred to as COB, are several light-emitting diode chips installed in a ceramic or metal substrate, programmed to function uniformly and produce a light seemingly coming from a lighting panel and not from individual light chips. This is basically what you need to know about them but to go deeper into the COB LED world, let us discuss the parts composing these lights.
The systems mainly include: the COB LED chips, heat sinks where they are attached to, LED drivers, and lastly, the wirings connecting the COBs to the drivers(1). These components are like the puzzle pieces that fit and go well together to build COB LED lighting units, including the grow lights used for indoor plant cultivation.
What is a COB LED lighting system without the main stars, also known as the LED chips, right? Manufacturers design and create each unit or system differently, addressing specific needs while maintaining general productivity. The products come with datasheets which explain their details and characteristics. For convenience, COB holders are available in the markets if you do not know how to solder and have no interest in doing so. Other useful add-ons are reflectors. These reflectors can help you achieve a more focused light beam and coverage.
LEDs, in general, are known for emitting less heat compared to other lighting systems. It is a must then for COB to uphold this reputation. This leads us to the second essential part of COB LEDs, the heat sink. Heat sinks are installed to protect the units from overheating. What they do is transfer the accumulating heat away from the LED chips, keeping them cool and free from damages. Thus, without the heat sinks, COB LED lights would lose its charm to other growers.
Energy comes in different forms. LED drivers convert the electric power from the outlet to a form the chips would be able to utilize. Without the drivers, there would be no light for your plants! And to connect the whole equipment to the electrical source, the wires do the job for us. If you think about it, the drivers “translate” for the COB LEDs to “understand” and the wires serve as the bridge.
What are the differences in other LED types from COB LED?
A study entitled “An Update on Plant Photobiology and Implications for Cannabis Production” (2019), explored the growing interest of growers for light emitting diodes (LEDs) because of their long lifespans, adjustable light intensity and quality, and efficient production of light with little energy (2). The study even compared LEDs and HPS (high pressure sodium) lamps and found out that LEDs are winning in terms of controlling periodicity, quantity, and spectrum of light.
Over the years, multiple varieties and types of LEDs have been released in the market. The three most common types are DIP, SMD, and COB. DIP (dual in-line) LED lights were on the older side of lights under LED and they were popular in the past for their bright and durable lights. However, if we are talking about indoor growing, DIP would not be the best choice as one unit can only emit 4 lumens (3). These lights are made out of a chip inside a plastic casing with two pins connected to it. SMD or surface mounted device, on the other hand, known for its three colored (red, blue, and green) diodes. This means SMD LED lights can offer a variety of light spectrums that can be advantageous to growers who are replicating the natural sunlight for their plants. They are made out of light emitting diodes which are boded into a circuit board.
These three types are of the same technology, right? How do they differ from each other? There are a few points which we can look at to compare and contrast these lights. First is their production of lumens. Lumens are used to measure brightness. And if you are into indoor growing, brightness is essential. It makes the plants thrive and thus, produce more yields. In terms of lumens, DIP loses in this round. As said earlier, it can only produce 4 lumens per LED. SMD and COB are good choices under the lumen criterion. Both produce large quantities of lumens with a little amount of electrical energy used. An obvious difference among these three is their appearance. DIP looks like a tiny bell with pins as legs, SMD has several varieties which all look different, while common COB LED lights are yellow circles with little chips on them and metal or ceramic boards where they are mounted to.
Advantages of COB LED Grow Lights
Knowing all these about LED lights, what would be the benefits of choosing COB LED grow lights? You may have heard they initially cost more than the other types of lights in the market. Are they worth the shot?
There are three categories we can investigate to see if investing on COB grow lights are worth the shot. These categories are: efficiency, light quality, and product design. The efficiency category focuses on answering the question, does it provide more? This category is concerned with lifespan and energy efficiency. Light quality, on the other hand, addresses whether the light emitted by COB can beat the other light sources. Are COB grow lights the best you can provide for your plants’ needs? Lastly, product design is all about reviewing the components and physical features of COB.
In terms of lifespan, there is no question COB LED lights could outlast most grow lights out there. These light systems claim to last for at least 30,000 hours (4). That is more than 3 years! And I wrote “at least” because it could even live through 60,000 hours. It may cost a little more than the other grow lights but you are paying for its longevity. Imagine, other light sources may require replacements or repairs only after a year but your COB LED lights are still strong as ever.
Given the multiple diodes installed in a unit, COB LED lights can produce a higher amount of light consuming only low electrical energy. Data records show that COB produces 1.8-2.5 µmol/j(4). The least recorded for COB is even the most µmol/j for other artificial light sources. That is saying something. It means both you and your plants are benefitting immensely by using COB.
Now onto the quality and type of light COB lights produce. COB does not emit various colors, unlike SMD. It can only produce white light. This can be a disadvantage to other growers who want to customize the spectrums according to their plant needs. However, the white light COB emits is not a simple “white” light. COB is also known for its high color rendering index (CRI). High CRI means higher realistic touches to the light. No intense yellow or orange colors but you get high quality white light (4).
Do you remember our lessons about the components of a COB LED light system earlier? As COB is known for generating lower heat, it is all thanks to the heat sinks incorporated in it. The heat sinks reduce the possibility of overheating which may, in turn, cause dried and scorched leaves or worst-case scenario, fire. Beside, common LED products are designed to generally produce little to nothing infrared light which makes the lights feel warm. Little infrared equals little heat.
Elaborating more on COB’s physical features, most products are designed to withstand all kinds of weather. They have protective characteristics which make them durable and strong against conditions such as moistening, rotting, oxidation, ultraviolet light exposure, static electricity, and dust accumulation(5). They are also abrasion resistant, making them look good as new even when the time has passed by.
Last but not the least, COB LED lights are space savers. COB packs multiple diodes in a single substrate, providing you with even more lumens than other types of individual light units lined together. They are compact and would be beneficial for growers who have small grow rooms in their houses.
COB LED lights offer a lot of advantages for growers who are willing to spend a little bit more on quality lights. They have easily passed the three categories we laid down above. Efficient, quality, and impressive designs, what more can we ask for?
Which is better COB or SMD LED?
We have briefly tackled this earlier in a previous section but let us go through a more in-depth discussion this time. COB and SMD are probably the two types of LED fighting for the “best LED” title. You may ask, they are of the same technology, right? Why pit them against each other? Okay, point taken. However, the rationale of this section is to enlighten you of the differences these two have and to help you choose which suit your plans and needs more as an indoor grower.
The advantages of using COB have been discussed above, and now, for a change, let us focus on comparing the “downsides” of both types of lights.The main difference between COB and SMD roots from the light spectrum they can offer. COB only emits white light while SMD can offer various light spectrums because it has three colors of diodes. This is not an outright disadvantage nor advantage for the both of them so let us treat them as double-edged swords. COB cannot be tinkered to produce specialized spectrums yet SMD does not release sunlight replica because its light can come off too intense or extreme.
SMDs cannot be utilized for big factories and commercial productions as they are not designed to accommodate high voltages. This is definitely a disadvantage if you are thinking of installing SMD LED lights for your huge greenhouse. Hopefully, in the near future, manufactures can design safe and efficient SMD grow lights for large scales.
Now for a con of COB, COB LED lights have some problems with “spreading.” This causes some unattended spots in plants which are not reached by the grow lights. You may strategize on the proper spacing to avoid this but using small SMDs would be beneficial in this situation as they can address the spacing problem.
Cree and COB LED
Cree, Inc. is a popular manufacturer and marketer of different varieties of LEDs over the years since 1987 (6). Their products span from LED bulbs, chips, and of course, grow lights. Their grow lights’ features usually include options to adjust light intensity, cooling systems to avoid overheating, high-quality white light, and long lifespan. Again, as the main downside of any COB LED light, Cree’s variations are also costly. The price is worth it as you can acquire help your plants flourish and thus, produce more yields in the long run. Just endure the broken pockets first, you will gain a lot later!
COB LED vs SMD LED
Let us use this section to summarize what we have gathered about COB and SMD, their similarities and differences. First, both COB and SMD are known for providing high amount of light while consuming low electrical energy. This is probably the best deal a grower can get from his grow lights. The plants are thriving under the bright light and you get to spend less on electricity? Just wow. Second, these LED lights generate less heat compared to other light systems. With COB and SMD, overheating will not be in your worries. Their diverging point is the spectrum of light they emit. COB releases realistic white light while COB can give intense varieties of spectrums. It is up to you whether you like a light source which mimics sunlight or specializes for your plants’ needs.
In conclusion: Are COB LED grow lights better?
There are always two sides to every story. There would be arguments for and against an item’s reputation. Some would claim A is the best, others would say it is B. Now, COB LED grow lights are in the spotlight. Let us briefly go through again the advantages and disadvantages of these lights to determine whether the benefits outweigh the downsides.
COB prides itself for its impressive lifespan. It outlasts other artificial light sources by, not to brag too much but, more than 10,000 hours. The grow lights can also emit a high amount of light with only little electrical energy. In addition, it emits realistic and high-quality white light which attempts to replicate the sunlight, making it favorable for your plants’ needs. One more good thing about COB LED lights is that they have built-in heat sinks which help regulate heat emissions by the lights, making the unit run cool. The lights also come in durable designs! As for the major drawback, COB units are expensive. They cost more than the other market options.
Weighing all of these, the advantages outnumber the negatives of COB. It could also be argued that the cost, which is the major “disadvantage” of COB, is reasonable for it provides high quality, durable, and long-lasting lights for your indoor plants. You can always get your money back after your plants have produces the flowers you have been waiting for. So, the short and simple answer to the question posed above? Definitely a yes.