Thermal Management

The term “thermal management”, or heat management, is important because it’s easy to overlook the impact of environmental conditions on LED performance. Failing to consider factors such as ambient temperature, humidity levels, and exposure to external elements can lead to suboptimal performance and ultimately system failure for each of your LED grow lights. In terms of your plants, excessive heat from grow lights can stress or damage plants, affecting their health and productivity such as light burn, powdery mildew, pest infestations and nutrient burn ultimately impacting the plant’s roots, foliage, and flower production. Make sense?

If the LEDs burn too hot it results in rapid degradation of the LEDs themselves resulting in less light output, shorter life while impacting your HVAC.

The rule of thumb is that for every 1% decrease in light output there is 1% less yield. That’s why if a grow light that degrades over 10% it is considered at the end of its useful life.

This degradation may prompt you to increase your output impacting your ROI. Coupled with premature degradation of the driver, or power source, due to excessive heat has been arguably the cause of most grow light failures across the country.

And, if that’s not bad enough, it will also cause color changing or color shifting… meaning your proven spectrum, or the cornerstone of your profitability, is going to change!

What’s happening is the LEDs are coated with various phosphors which helps to create a spectrum to mimic sunlight. Excessive heat also burns off the phosphors, causing color changing or shifting. While this might not matter much for parking lot lighting, roadways, or other non-horticulture it’s crucial for your grow operation, as your plants rely on a proven spectrum for optimal growth.


Heatsinking, crucial for all electronics, transfers heat away from the PCB components while in use for this reason. Aluminum, which is a cost-effective excellent conductor of heat, brings the operating temperature down. Every square inch of surface area of the circuit board is attached to an equal size of aluminum. By adding aluminum fins will further enhance heat dissipation. This well-designed heat dissipation system prevents overheating, preserving the performance & life of the LEDs, stabilizes the temperature thereby enhancing plant growth and reduces HVAC costs.

Look, our cell phones are electronic devices, right? But why aren’t the casings plastic? Answer, it’s because the casing doubles as a heat sink. If that wasn’t the case, don’t you think someone would’ve come out with plastic casings by now to cut costs?

So why don’t all LED companies know this? The engineers in China probably do. But once again, you guessed it—it will also cost them money & make their prices higher. ALSO, by widening the printed circuit board, using more lowered powered LED chips and more heat sinking, the cooler the LEDs burns and the better the uniformity. That’s HUGE!! But it costs more money. All things being equal, at the end of the day, you get what you pay for. Contact us if you’d like to chat about it further.

Uniformity Ratios

The crucial max/min and avg/min ratios, often referred to as the uniformity ratios. They are a measurement of how evenly distributed the light is spread across the crop’s canopy.  These ratios will assist in determining to what extent a grow light will optimize a room of plants giving the investor a higher ROI.    They can be calculated rather accurately with the proper computer software.

It’s been my experience that these critical ratios are seldom discussed because the results don’t help sell most grow lights…surprise!!! (if you know what I mean), and the ratios are not well understood by growers or the resellers.

Let’s try and clarify things.  Unless you’re growing in a 4’x4’ tent light maps like this one are of very little value due to the fact that they don’t factor in spill light or cross-lighting as well as reflective light.   The ‘Spill light’, or cross-lighting, is the illumination from one light spilling over to the area under another light which is likely considering an LED has a 120-degree optic built into it and they’re commonly hung at least 18” over the canopy.

So, let’s discuss these 2 uniformity ratios.

  1. The Max/Min Ratio (Max/Min)
    • It’s a ratio of the brightest spot in the room to the darkest spot in the room.   It’s usually found here on your calculation page right here.   If there’s a big difference, generally more than a 2.5, it means some plants are getting much more light than others and you might want to consider another option.  Which could simply mean you may need to add additional fixtures or try another brand of grow light.
  1. Average-to-Minimum Ratio (Avg/Min) in Horticulture:
    • This ratio compares the AVERAGE PPFD everywhere in the room TO THE DARKEST SPOT.   It’s usually found here on your calculation page.   Again, generally over a 2.5 is considered poor.    If however, the average is close to the darkest spot, or a ratio under 2.5, it means the light is spread relatively even across all the plants.

Ideally this metric should be close to ‘2.0’ or less.   Since a ‘1’ is perfect uniformity which is usually not cost-effective to achieve anywhere between a 1.0 and less than a 2.0 is great.

In summary, a comprehensive approach should be taken when making a final decision on uniformity.  While the avg/min ratio assesses overall uniformity of light distribution, and the max/min ratio focuses on identifying areas of extreme variation in light intensity. Both ratios, when taken together, are important for optimizing growing conditions while identifying variations in plant development and minimizes stress on the plants giving you a higher ROI at the end of the day. Hope all that makes sense.   Contact us if you’d like to chat about it further.

LIGHT LOSS FACTOR (LLF) & Reflectivity ratios

Have you ever heard of anyone talking about Light Loss, LLF or reflectivity factors? Probably not. What they have in common is when your computerized layouts and PPFD calculations are being generated for you by the grow light company, or reseller, they are making 2 crucial assumptions on your behalf. Unfortunately, they can significantly skew your results.

The Light Loss, or LLF is a multiplier factor that appears here on your PPFD calculations page. It is used to predict PPFD performance, or the percentage of light that is actually hitting your plant’s canopy…. at least on paper. The thing you should know is that metric represents the light being new and out of the box.

The key word here is ‘percentage’. So, in this case, the number 1 indicates that the light is putting out 100%. This is used by most of the industry. But, what you should know is you will never get factor even after minimal usage for 2 reasons. One, because LEDs degrade over time from excessive heat and two, grow room debris such as water and chemical sprays as well as dust and dirt to some extent ends up covering the LEDs.

The Reflectivity factor is also running in the background that can skew your PPFD results. The reflectivity factor is a metric that represents how much light is bouncing off the floors, walls and ceilings. Because every paint color, type of material & texture has a reflective metric associated with it the person who is generating your PPFD metric is making an assumption on your behalf. For example, he can make a gray wall white or a white wall into mirrors.

It all adds into calculating the PPFD. I’m not saying that anything unethical is going on, but rather, you should simply know that with a simple keystroke your PPFD calculations can be skewed.


Let’s discuss the LED grow light’s driver. The driver is the power source or heart of the LED grow light. It doesn’t seem to get the attention it deserves inspite of it being the weak link of the system. The driver is usually located either in a box built into the grow light or remote, meaning it has removable mounting brackets on the back of the light or hung off to the side in a plug & play manner. A remote driver is preferable because proper ventilation is critical for preventing heat buildup. Elevated temperatures can compromise performance and longevity of the driver.

Like any other product on the market there are different levels of quality. They can have a life of only 10,000 hour which translates to a couple of years growing Cannabis on a 12/12 growing cycle. Or, as much as 50,000 hours or about 11 years depending on the system’s operating temperature and quality of components. This goes back to our #1 video in this series on thermal management. You might want to review that video.

AND…’s a fun-fact for you…. ALL drivers have a shelf life. Yes, even if they’re not used, they’ll go bad after about 7 years due to the capacitor degradation. Inventronics, one the most highly respected names in the driver industry, shared with us that they dispose of any drivers not sold after 1 year from the manufacturing date. So, beware of grow lights that have been sitting in someone’s inventory a long time it’s going to lessen the time they’ll operate for you. Quite frankly, I’m not sure how you can ensure you’re not getting old ones because nobody puts an expiration date on them like the food industry.

You may also be interested in knowing these 4 things about drivers:

  • You can’t just take any driver off the shelf, plug it into your light and expect it to work. The amperage and voltage of your system voltage need to match up to the driver.
  • Not all drivers are dimmable.
  • An efficient driver will save you energy. You want an LED driver that has efficiency of at least 90% or higher. Meaning, the more efficient, the less heat it will generate and the less impact on your HVAC. You might want to look at that metric before buying.
  • Driver features such as surge protection, overcurrent protection, and temperature compensation are important. These features can help to extend the life of the LEDs and improve your LED lighting system performance.

And finally, some LED grow light companies make their own drivers. So, it is important to choose a grow light that uses a driver from a reputable brand. This will help to ensure that you are getting a high-quality product that will last for many years. Simply do a Google search.

Industry Certifications…What They Don’t Tell You.

Although most grow lights have the proper industry certifications, it is still littered with poor quality products and questionable marketing tactics.

The UL and ETL are safety certifications to keep you from electrocuting yourself.  The DLC certification, which stands for Design Lights Consortium, provides the industry a valuable resource because it is a performance certification that ensures you that a light meets certain minimum performance metrics set by DLC.  Many utilities require this certification to qualify for you for rebates.    DLC is sort of a clearing house that reviews the data generated from independent 3rd party test facilities.  If a light meets their standards, they issue the certification and posts it on their web site at   All marketing materials with this certification must match their web site.

But, you should know that it doesn’t necessarily show the actual performance of the whole light over time.   The key words are ‘necessarily’ and ‘time’.    Let me explain:

Let’s look at the tests that DLC they are reviewing.  These tests are called LM 79, LM 80,

LM 84 & there’s a few others:   I’m not going to go into the details of each of those tests because you can Google them.   But you should know 2 things:

  1. Performance test data for each component of a light must be tested for a minimum of a 6,000 hour period, or for 8.5 months. It is done in a lab type environment. Then, based on its findings, they make projections of up to 50,000 hours, or 11.5 years.
  2. And 2, note, they’re NOT testing the whole light over 6,000 hours. They are only reviewing component data.  Meaning, the chip and driver manufacturers do not know that the LED chips or drivers are going into a commercial grow light let alone the horticulture environment.

Because the test facility does not test the grow light’s ability to stand up the harsh elements of an actual grow facility over time, could this be why THIS this grow light from a popular manufacturer who had the proper certifications had to issue a document with this image as a fix for their light falling apart?

And could this, and similar other issues, be why there’s been so many failures in the industry over the last few years?

The bottom line is that even with creditable industry certifications, there’s no guarantee of longevity of performance or construction.    And, just a few grow light failures could have dire consequences to grow facility.  Should too many of them fail it could be catastrophic.

Although the industry certifications are a great first step.  At the end of the day, nothing replaces contacting references who have had that light operational for at least 5-years because one of DLC’s requirement is for a grow light to have a 5-year warranty.   And, if they are going to hand out a 5-year warranty, don’t you think they at least should have been in the grow light business that long?!      Even the lowest quality lights can perform comparably well for a year or two.  Nothing replaces contacting the references.  This will also give you an opportunity to ask about customer service—or the lack of it.

Conformal Coating

I don’t hear anyone ever talks about what’s involved with protecting the LEDs on a grow light. ]. Conformal coating is a protective acrylic layer applied to most electronic circuitry. In grow lights to safeguard against moisture, dust, chemicals, and temperature fluctuations. It prevents corrosion, short circuits, and damage, ensuring reliable performance in humid, dusty environments. Additionally, it offers chemical resistance, thermal stability, and electrical insulation, prolonging the lifespan and efficiency of the grow lights. It does not significantly affect the transmission of light since it is a transparent layer that adheres directly to the surface of the components.

By contrast a glass lens or optic can absorb & reduce around 8%-11% of the light passing through it. This absorption can result in some loss of light intensity compared to conformal coating.