question about heat please help might miss a good deal

az2000

Well-Known Member
That's really informative(!). I assume that's a forum thread and you can't go back and revise the original. I suggest you put that in your "Grow Journal" (blog post) here and update it as you learn more (like my "How I grow" linked in my sig.). That could be similar to an FAQ. Referenced repeatedly.

However....

You left out LED lightbulbs. They aren't quite as experimental and small-grow as SMD strips. And, they're not as dubious as the Chinese grow lights (which show bulb-sized blurple lights). With PAR38s and some bulb sized sidelight, I did this.

That wasn't a small plant (a little over 3' tall, in a 3x3 space.). Just five PAR38s on top, two on the side, and five lightbulbs (for 21w/sq ft).
 

SupraSPL

Well-Known Member
Corey from Black Dog LED (Colorado) was interviewed on the Adam Dunn Show, seems like he has some decent knowledge but that does not seem to be reflected in the product IMO. I would be willing to bet he will jump on the COB bandwagon at some point.

LED talk starts around 1:25:30
 

az2000

Well-Known Member
It's a forum post, and I can edit it, I've been revising it the past few days probably over 40 edits so far.
Typically, forum posts become uneditable. Without a limit like that conversations may not make sense when read in the future (if a quoted post is drastically different). That's why I always think in terms of a blog (or wiki) entry for topical, structured, expanding information.

If you add a section about household lightbulbs, I would mention not all products found on the store shelf will work equally well. (It's not as easy as buying CFLs, which are created more equally?).

For example, the spectrum of a light may not be as suitable as another? Or, a plastic diffusion dome may reduce the efficiency compared to the clearer glass of a PAR38? As far as I know, only Cree and Phillips have been used on this forum. (And Cree introduced the cheap "4Flow" which may not live up to the glass/finned model which has been used here.).
 

frica

Well-Known Member
e: The BDL website has some good read :) I especially recommend the 'The Efficiency Myth' section.
"Chip-On-Board (COB) or "Integrated" LEDs are created by placing many low-wattage (typically 0.5W or 1W) LED dies side-by-side on a circuit board. This allows companies to claim very high wattage LEDs, but for example the "50W LEDs" are just 50 1W LEDs side-by-side (or 100 0.5W LEDs). It isn't possible (yet) to make long-life COB LEDs with higher-wattage dies, as it isn't possible to remove the heat from the COB assembly quickly enough to prevent damage to the LEDs. For example, there are now some COB LEDs made with 3W dies on the market, but these are still only run at 1 watt per die and still have a tendency to burn themselves out within a couple months. COB LEDs also often lack primary lenses on the LEDs, which actually diminishes the light output from the LED."

Oh god.
I really hope somebody fucks their owner up.
 

PicklesRus

Well-Known Member
Typically, forum posts become uneditable. Without a limit like that conversations may not make sense when read in the future (if a quoted post is drastically different). That's why I always think in terms of a blog (or wiki) entry for topical, structured, expanding information.

If you add a section about household lightbulbs, I would mention not all products found on the store shelf will work equally well. (It's not as easy as buying CFLs, which are created more equally?).

For example, the spectrum of a light may not be as suitable as another? Or, a plastic diffusion dome may reduce the efficiency compared to the clearer glass of a PAR38? As far as I know, only Cree and Phillips have been used on this forum. (And Cree introduced the cheap "4Flow" which may not live up to the glass/finned model which has been used here.).
A WIKI, that's an excellent idea! I'll set one up on LEDBuilder.org. It can be used as a glossary of terms too.

Hopefully I won't be the only one contributing to it! I noticed there used to be info on WIkipedia about Lumileds, but ti was all pulled down. At least this way if we have our own wiki information we add will stay there...
 

PicklesRus

Well-Known Member
On Wed, Dec 30, 2015 at 8:20 PM, pickles <[email protected]> wrote:

From: pickles <[email protected]>
Subject: Your comparisons are missing a vital component

Message Body:
You need to compare the amount of usable light VS watts consumed:

umol / W

It looks like this site was made by blackdog, if you included that information I don't think Blackdog would be rated so high.

Knowing which company "doesn't lie" to you is kinda moot - I contacted blackdog today and asked them directly how much light they product for the electricity consumed and they danced around the question, and they even say "efficiency is a myth" when it is a core fundamental principal of all electronic design.

Not super impressed with that, but you could make your site better by fixing that data. That is of course unless you're sponsored or owned by Black Dog LED, which it looks like you are.

Check this out - it's not refined enough to explain things in good terms, but it's a work in progress. The huge piece you're missing is efficiency in umol(par) per actual wattage.

We we all really want to know is:

umol / W used
umol / $

$/W is meaningless
$/usable W (PAR, or Par watts) is what matters.

You could even calculate $/wasted W... that would show how much electricity you feed in gets wasted and not turned into plants.

Seriously!

--
This e-mail was sent from a contact form on Compare LED Grow Lights (http://www.compareledgrowlights.com)
 

PicklesRus

Well-Known Member
The reply:

Hello,


Sorry, I'm copying-and-pasting from my replies to your comments on the site for a lot of this...


I'd love to compare all of the lights based on cost per amount of usable light produced! Unfortunately, I don't have all the data to determine that. I need to know how much light is produced by each light (and how much of it is truly usable by plants) and this information is simply not available. Sure, some companies give a PAR number (or 10 or 20) for their lights, but these numbers are often deceptive; see my breakdown of a PAR deception to see how. Basically, I would need to get each of the 150+ lights I'm comparing, measure the light output fairly (as in at many, many points across the entire advertised footprint), rate it on both average PAR and consistency of coverage, and only then could I actually rank the lights based on cost per amount of usable light produced. I don't have the money or time to be able to do that for all lights. To really do it right I'd need a huge integration sphere (we're talking $20K plus) to measure total light output from the lights.

However, I did recently get an awesome StellarNet spectrometer and I will be analyzing the PAR output of as many lights as I can. The new hands-on review section is coming very soon!

When ranking companies based on PAR output per dollar, I also doubt that Black Dog LED would be at the top of the list; there are a lot of really cheap LED grow lights out there that would certainly be less expensive per light output. However, the really cheap lights also tend to be of poor quality, and at least to me it doesn't matter if I can get a lot of light for a low cost if the light breaks or degrades quickly, has a poor spectrum, has extreme hot spots, has a poor warranty, etc. The whole point of this site is that there are a lot of different things to consider when making a purchase, and I feel it is important to consider all of the different categories I am comparing things on to get a fair overall picture. This is where Black Dog currently comes out at the top- compared across a broad range of categories. If you're only interested in comparing lights on one thing, that's why I have all the categories broken out- go look at the one category you're interested in and pick the best light for you!

Completely agree with you that $/W is kind of meaningless, but it is the best comparison I can make with the data I have for all of the lights.

As far as your comments about not caring if companies are lying to you, I'm baffled. If a company is lying about the specs of their light, how do you know what you're really getting when you buy it? Lying about specs or performance is a big deal; look at what just happened with Volkswagen with their lies about emissions and gas milage performance. The new hands-on reviews I'm putting up (hopefully this weekend when I have time) show that Kind LED is blatantly lying about their spectrum- the lights I tested of theirs have no UV, the spectrum graph my spectrometer gives me is very different than the spectrum graph on their site (and other people's spectrometers agree with mine, not Kind's), and their PAR measurements were taken only in the center 3 feet of their claimed 5x5 footprint- in truth they don't light up the sides of the footprint at all! So they are lying and I would very much care about it since their light is not what they claim it is. It will not cover the area they claim. It does not have UV to get increased THC/CBD/trichs like they claim it does. So yes, I care about the lies, and I'm baffled as to why you wouldn't be?

As far as Black Dog saying efficiency is a myth, I must have missed that on their website- can you point me to where it is? If they're lying I'd certainly include that on compareledgrowlights. I do see their "Efficiency Myth" page at https://www.blackdogled.com/efficiency-myth but from what I read on there they aren't really saying efficiency is a myth, they are just saying that using the most-efficient LEDs doesn't make the best grow lights because they aren't as bright as they need to be.

I started this site because I got badly burned by my first few LED grow light purchases many years ago, with lights that did not perform as advertised. I do grow with Black Dog LEDs and have over a dozen of their lights. Every chance I get I check out other lights and now that I have a spectrometer I'll be measuring spectrum, PPFD / PAR as much as possible and posting that up on this site.

Cheers!
 

PicklesRus

Well-Known Member
My reply

Hi, thank you for replying – If you are actually non-biased then it’s just a matter of time until your site becomes more accurate (and you do have a ton of content on there, it’s an impressive amount of work good job).


Cost – $/W should have a red Astrix next to the chart title and say: “Important info below, please read” – Since you know better, you should add info and maybe a column $/PAR even if it remains “data not yet available” in each cell. You should be calculating Par/$ of upfront cost, as well as PAR/W so people know how much they are going to pay to run the light and how much it will be upfront to buy it.


If you can’t measure electrical efficiency, you should highlight it on your site with caveats around LED lights that are run at higher currents.

If your goal is to inform people from an un-biased standpoint, you should incorporate electrical efficiency to help people be aware that it’s an area that hasn’t been properly assessed yet, but may have important implications (Commercial growers, financially limited growers, people living in high-energy cost areas). Even having a table of data with a bunch of question marks or “not yet tested” would show people that it is important, but we can’t get the info.

Higher current = LED Droop = less efficiency = wasted electricity ($!). That should be a huge point on your site.


Blackdog’s Efficiency Myth article
By selectively using technically correct but incomplete information, the article in my opinion looks written to detract people from using technology they aren’t invested in (COBs and High Efficiency design).

There's a video online that shows 1.9G/W with the new CREE COB LEDs, and “never under 1GPW since switching to COBs”

That’s impressive isn’t it? Especially since they run very cool when properly heat sinked and efficient when powered correctly… but you can’t verify that, so let’s look at this:

Excerpt: “It isn't possible to remove the heat from the COB assembly quickly enough to prevent damage to the LEDs.”

Do you think this is an honest statement? I don’t. That would mean Large top-end COB manufacturers are making COBs for commercial product application that fail quickly. If you take a 5W led and don’t put adequate cooling on it, it will fail too.


Excerpt:”COB LEDs also often lack primary lenses on the LEDs, which actually diminishes the light output from the LED”

With all of the lens and optic products available on the market, is it honest to say this?


Excerpt: “Efficiency is incredibly important, but it doesn't matter if your LED grow light is the most efficient if it won't grow plants well.”

What about lights that are efficient that do grow plants well? BML Spyder grows plants well, and are more efficient. It’s like they are actually saying “Efficiency is important, but efficiency isn’t that important”. It’s technically correct but misleading. Which in my opinion is dishonest.


Excerpt: “the best combination of efficiency, spectrum and plant-growing power available on the market.”

Can anyone truthfully say they have the best combination of anything on the evolving LED market?

That video of the guys who performance tested blackdog in one of those 250,000$ light orbs showed it produced the most light, but had the highest wasted energy / usable light ratio than any other light tested.

You really believe this is honest?




Frankly, it looks like you’re picking on everyone but BlackDog.
 
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