LEDs - Myth busting and the ugly truth.

Discussion in 'Growing Marijuana Indoors' started by tylerm428, Jul 31, 2013.

  1. #1 tylerm428, Jul 31, 2013
    Last edited by a moderator: Jul 31, 2013
    Myth#1 - LED is more efficient than HPS
    HID Lighting (HPS and MH are both types of HID lighting) is the most efficient form of artificial lighting known to man.  LED lighting is actually much closer to T8 florescent when you look at efficiency.  Which is still better than CFL.
     
    Don't believe me?  Do your own research you'll find the same thing.  A high quality (expensive) LED fixture can be as efficient as 100 lumens per watt while cheap LEDs are approx 60 lumens/watt.    An expensive HPS fixture can reach upwards of 150 lumens/watt while cheap analog fixtures still come in at 85 lumens/watt.  HPS can be upwards of 50% more efficient than LED.   Check out this Wikipedia article if you don't trust me:    http://en.wikipedia.org/wiki/Luminous_efficacy   The article has a great chart at the bottom that shows the luminous efficiency of different light sources.
     
    Myth#2 - LED produces less heat than HPS.   Efficiency and heat are directly related.  All wasted energy turns to heat.  Therefore a more efficient light source produces less heat.  We just established that HPS is more efficient than LED so the truth of the matter is that LED produces more heat.  Here's an example: 1000W HPS and LED fixtures.  Let's assume that they are both high quality fixtures so the LED will be approximately 15% efficient while the HPS will be approximately 22% efficient.   That means that the LED fixture acts like a 850W heater in your room while the HPS fixture acts like a 780W heater.  LEDS just seem like they run cooler because that heat is spread out over a larger surface area.
     
    LED's do have some advantages tho that IMO even out the odds.  LED fixtures do not require a reflector and therefor do not suffer from efficiency losses due to a reflector.  LED fixtures can also be fine tuned to produce more light in the spectrums that are useable by cannabis plants whereas the output spectrum of HPS lighting is mostly fixed and can't be influenced much.  LED fixtures spread out the heat over a larger surface area resulting in less fire hazard and less hot spots in your room.  LED fixtures can be more flexible in their shape/design.
     
    Net effect is hard to measure when it comes to your plants.  But all things considered - I would say that equally sized high quality LED fixtures and high quality HPS fixtures will produce roughly the same results in your room.  The main difference being that the LED fixture cost 3x as much.

     
  2. I have little grow experience, but been researching a lot and will go ahead and say with reasonable confidence:
     
    1)  Lumens have nothing to do with measuring the effectiveness of a light on plants growth (it's PAR)
     
    2)  Im not sure where you're getting all this heat mumbo jumbo, as from my understanding they produce way less heat.  Assuming those 15% and 22% numbers were true you would still need only half as much power for Leds so really when you add 15% up twice(or cut 22% in half) its actually less in total watts.
     
    So just to sum up there are a lot of wasted lumens($$) not being utilized by the plant in HID not to mention all the excess heat($$) produced from the HID, requiring cooling methods($$) to get rid of the unwanted heat we are creating.
     
    So yes there may be a higher upfront cost, but I suspect they will come down in time as this tech is basically brand new.  In addition you are saving roughly 50% on your energy costs every day you are using your grow lights. 
     
     Someone correct me if I am wrong
     
  3. LEDs are the future
     
  4. #4 DWC4Life, Jul 31, 2013
    Last edited by a moderator: Jul 31, 2013
    Idk what you are going on about heat...because I can tell you thats entirely wrong. You have one thing linked thats factual, the rest is your own speculations.
     
    "1)  Lumens have nothing to do with measuring the effectiveness of a light on plants growth (it's PAR)" <--- Correct
     
    And where are you getting LEDs cost 3x as much? Prices on Amazon or something? Do some shopping around, you can get a LED setup of the same equivalent wattage for nearly the same price (a little more usually if you want to buy a quality piece of gear). PS: You can literally just BUY the strands of LEDs
     
    You also forgot to mention the fact that LED's are tiny compared to HPS/MH hoods. Someone who is limited on space will benefit from LEDs greatly vs MH/HPS setup.
     
    I think the benefits should be more laid out like this; Size & Space/Heat Output/Power Consumption/Ability to customize light spectrum of output PER row of diodes, etc. I'm sure I could come up with a few more if I wanted to...lol
     
    "Let's assume that they are both high quality fixtures so the LED will be approximately 15% efficient while the HPS will be approximately 22% efficient.   That means that the LED fixture acts like a 850W heater in your room while the HPS fixture acts like a 780W heater.  LEDS just seem like they run cooler because that heat is spread out over a larger surface area."
     
    ^ What? Where the heck are you getting that LED's are LESS efficent than HPS? I'm not sure where you are getting your info, but its not right. LEDs are known to be up to 50% (Even more in some cases, just depends on how well the unit is built) down in power consumption than the same wattage HID setup.
     
    This thread should be titled: "Why I think LED's suck compared to HPS" :p
     
  5. I wouldn't even consider growing until LED's reached a price/performance ratio I was comfortable with.
     
    My three Pro Grows cost me $1100, and would have been $1000 if I had bought the two 260's at the same time. They are worth their weight in gold.
     
    In addition to the other benefits listed, I'd like to point out that LED's last many years (if a quality product to begin with).
     
    I've already theoretically made my money back on my whole setup by not having to buy any bud for the last few months.
     
  6. #6 tylerm428, Aug 1, 2013
    Last edited by a moderator: Aug 1, 2013
    3 people telling me I'm wrong, but none of them have provided any information either.
     
    PAR - Yes, I know what PAR is. Which is why I said: 
     
    The description "Light in the spectrums that are useable by plants" is the definition of PAR.  The fact of the matter is yes a properly designed LED fixture can have better PAR than a HPS fixture.  But considering that HPS already has good PAR for cannabis plants you can only improve by so much.  My argument is that the better efficiency of HPS more than compensates for the better PAR of LED lighting.  Lumens and PAR go hand in hand when discussing plant growth.  Anyone who does not recognize this relationship should not be posting in this thread.
     
    As for efficiency.  You guys obviously do not understand how lighting efficiency works.  Let me try to spell in out a little better.  Efficiency is defined as useful output divided by total input.     E = Pout/Pin
     
    If you have something that is 20% efficient it means that 80% of the energy you put into the system is wasted.   In the case of lighting efficiency that wasted energy shows up as heat.  Therefore a more efficient light produces less heat for the same amount of light output.   You cannot argue this folks - it's the laws of physics.  To get the same light output the less efficient light source requires more input energy all of which goes to additional wasted energy (heat).
     
    LEDs are not the be all end all of lighting.  There is a reason that you do not see much LED lighting in commercial and industrial buildings.  These buildings are designed by engineers and the engineers know what the best lighting options are.   They still use mostly florescent and HID lighting for general purpose lighting because it's the overall best choice. 
     
    LEDs do have advantages that make them a great solution for certain lighting scenarios.  They perform very well in cold environments making them an excellent choice for lighting in coolers and freezers.  They can be built into a low profile or small package making them great for under-cabinet lighting or lighting in any confined area.   They do not have a filament making them a great choice for high vibration locations.  They are an almost instant on light source making them a good choice for low frequency strobe lights.  They have excellent lamp life making them a great choice for locations where changing the lamp can be very difficult/expensive.  They can be built to output a very narrow light wavelength making them a great option for when you want colored light.  They have a very directional output making them great for accent/spot lighting, flashlights, etc.   Trust me - I know my shit when it comes to lighting and LEDs.  LEDs are great and have many useful properties.  However, a super high efficiency is not one of their useful properties - there are better choices for that and as growers we do not require any of their other benefits to make them worth the extra cost.
     
    Speaking of cost - to whomever contested my point of a quality LED fixture costing 3x as much as a HPS fixture.  I say prove me wrong.  Everything I've seen says at least 3x as much for a decent fixture.  Please don't quote some piece of EBay garbage as we all know that they are way over rated and don't work worth a damn.  And don't try to tell me it pays itself back in power savings - that would only be the case if LED lighting was actually more efficient than HPS.
     
    Please, if you don't believe me: Instead of just arguing with me do some research on your own.  Prove me wrong.  You'll quickly find that the only people saying that LED lighting is the best choice for general overhead lighting are same people that are selling LED lights or people with little knowledge on the subject parroting what they've heard from others.
     
    And finally.  LEDs are not new.  The 1st LED was produced back in 1927!  Although about 20 years ago a discovery was made that allowed LEDs to become much more bright making them an option for lighting instead of just indicators.   But since then there have been no major steps forward with LED technology - just some small efficiency gains and design improvements allowing for higher wattage LEDs.
     
  7. Im calling bologna. Ive seen led ressults with much larger harvests than hps when done correctly.

     
  8. I didn't reply to your thread to argue and even considered skipping it, because I don't really see the point of it. I decided anyway, to post my personal experience regarding how much my lights cost me and how happy I am with them. This wasn't to convince anyone, to say one thing is better than the other, but simply my input.
     
    I believe it is important to have both side's input if this is going to be an informative thread, otherwise it is just one person telling everyone else they're wrong and them doing the same in return. Those threads are buzzkills.
     
    You're obviously quite happy with HID bulbs, and that is great. But everyone has different circumstances for their grow. and there is no perfect light. All have advantages and disadvantages that one must account for.
     
    I weighed everything out, including upfront cost, running cost, light life, heat, etc. LED's are the only light that makes sense for me at this point and in my situation. I'm currently on my second grow and couldn't be happier.
     
    The same could be said about people who say that about HID lights. Just saying...
     
  9.  
     
    You were the 1 person I wasn't really referring to.
     
    Regardless - none of those benefits you reference exist.  At the end of the day LED and HPS usable light for the plants per watt is roughly the same.  LEDs do not cost less to run, nor do they produce less heat.  Lamp life is better but LED lamps generally aren't replaceable or replacement lamps cost an arm and a leg which ruins that benefit.   You do know that LED output and efficiency drops significantly over time right?  An LED lamp near the end of it's life will put out only 60% of the light it did at the beginning.
     
    At the end of the day - It's really a wash except LED costs a lot more upfront.  I will admit that LEDs do have an advantage when it comes to fire risk (which can be very important) as while they produce the same amount of heat - that heat isn't concentrated into such a small spot.
     
    Implying that I should do some research myself is just silly.  I've done it believe me.  But hey, if you can point me to any articles or information from an educated and non-biased source (don't send me to some website that sells LED lighting) I'm always interested in learning more.
     
  10.  
    Let me guess.  You did a controlled experiment here right?
     
    You ensured that everything between the 2 grows was identical with exception of the lighting source.  Exact same wattage, same room temps, same soil/nutrients, same ventilation, same genetics, same light cycles, same amount of time in veg and flower, same O2 and CO2 concentrations, etc.
     
    Alright, we're not fooling anyone here.  You did none of this and from the sound of it, it wasn't even your own grow.  You are not in a place to call anything.
     
  11. You got me. LED's are crap. I'm upgrading to HPS/MH. Where do you get your lights?
     
  12. #12 tylerm428, Aug 1, 2013
    Last edited by a moderator: Aug 1, 2013
    Won't take my word for it?  Maybe you'll listen to others:
     
    Google "Most efficient Light source"
    Very 1st hit:  http://www.treehugger.com/culture/quick-quiz-what-is-the-most-efficient-artificial-light-source.html
    Another great unbiased article:  http://www.p-2.com/helpful-information/blog/370-is-led-the-most-efficient-lighting-technology/
     
    Yes, they do not take PAR into consideration for growing plants but as already mentioned HPS has good PAR to begin with and it's improved efficiency over LED more than makes up for the lower PAR.
     
  13. #13 tylerm428, Aug 1, 2013
    Last edited by a moderator: Aug 1, 2013
     
    When you start throwing around sarcasm and insults it's a clear sign you've lost the debate.
     
    For the record:  I never said LEDs are crap.  They work about as well as HPS and have some other minor advantages.  I just don't think they are worth the cost and I'm tired of everyone drinking the LED koolaid around here. 
     
  14. No, I just don't really care. I researched on my own and came to my own conclusion of what was right for me. You, apparently believe I (and arguably others I'd imagine) made a mistake and was fooled out of my hard-earned money.
     
    I'm not going to go flying around the internet trying to find papers to convince you of what worked for me.
     
    I hope you enjoy your grow with your lights. I've had friends with great setups that I envied.
     
  15. Also, I never considered this a "debate". You have your opinion, and I simply offered my input from my perspective.
     
  16. Sounds to me like you are getting frustrated simply because something contradictive to say. No it wasnt my grow but is absolutely was a side by side comparison with the light being the only variable. Its sad when people believe they are right without accepting any other evidence. You are the one who is out of place to be so dismissive and rude.

     
  17.  
    I respect that.
     
    I also don't think you made a mistake.  At least, not a big one.  Given a choice between a free quality 1000W LED fixture and a 1000W HPS fixture I'd take the LED.    About the worst I can say is they you may have paid more than you absolutely needed to.
     
  18.  
    I'm getting frustrated because I've tried very hard to present my case with science and logic and to site reliable sources to back up my claims.   In return I get contradicted by people who just parrot back something they heard from someone else, or someone else's experiment (observation would be a better word), etc with little thought and no research behind it.
     
    Perhaps I was rude.  But C'mon you started it by calling my efforts "Bologna" 
     
    I'm sorry, but your friend's grow is poor supporting evidence.  It was not under your control and even if he believed the grows were intended to be identical they likely were not.  A lot can happen over a period of 4 months.  If this was a well documented experiment, under proper side by side conditions, etc then I would have a hard time dismissing it.  But citing your friend's grows doesn't even come close to that.
     
  19.  
    I would like to correct the ignorance you are spreading tylerm. First you say that eBay LED lights are garbage. This is only partially true as there are some excellent LED lights on eBay, you just have to find the right seller. Second you are trying to use wikipedia as a credible and reliable site. As I go to college and must write many research, I can tell you that wikipedia is not considered a credible source. Third mistake is your claim regarding prices. I purchased a very nice quality LED and an exhaust fan with a carbon filter for around the same price as a quality 600W HID setup would be alone. If you want I can post some pics for you of my beautiful ladies that are coming up on the 4TH flowering week. I am not trying to insult you by any means, I just think if you are going to make such a strong claim you should at least have experience using LED's to grow with and if you do have experience with LED's,  maybe you just had a poor quality LED. It takes a bit of research to find a manufacturer that is reliable and honest, but REAL LED grow lights are way better all around in my opinion. I am providing you with a resource on light absorption (http://hyperphysics.phy-astr.gsu.edu/hbase/biology/ligabs.html) and another source from NASA stating benefits of growing under LED lights ( http://www.nasa.gov/centers/kennedy/home/plant_growth.html ). Again I am not trying to insult you, but rather inform you tylerm.
     
  20. #20 jets420, Aug 1, 2013
    Last edited by a moderator: Aug 1, 2013
    [quote name="tylerm428" post="18439557" timestamp="1375330501"]I'm getting frustrated because I've tried very hard to present my case with science and logic and to site reliable sources to back up my claims. In return I get contradicted by people who just parrot back something they heard from someone else, or someone else's experiment (observation would be a better word), etc with little thought and no research behind it.Perhaps I was rude. But C'mon you started it by calling my efforts "Bologna" I'm sorry, but your friend's grow is poor supporting evidence. It was not under your control and even if he believed the grows were intended to be identical they likely were not. A lot can happen over a period of 4 months. If this was a well documented experiment, under proper side by side conditions, etc then I would have a hard time dismissing it. But citing your friend's grows doesn't even come close to that.[/quote]Well just to let you know, my evidence is not backed by opinion or what someone else told me. I have literally seen with my very own eyes, from quality charts that were kept for each type of lighting, leds have major potential if ised correctly. Im really not trying to be a dick and I did not mean to insult you either. I just believe that leds get overlooked and disrespected because it is a new concept. There are certainly pros and cons to both hid and led.:)
     

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