Lighting Bilbo's Brief Guide to Choosing Your LED.

[Mike-groglo]

"Heath Robinson contraption" is perhaps more often used in relation to temporary fixes using ingenuity and whatever is to hand, often string and tape, or unlikely cannibalisations.

or in our case expensive equipment that we take to bits and reassemble in what we think should be the correct order!

And yes, this is what we supplied to DT in order to start the ball rolling for our bespoke kit!

 

[Mossy]

"It seems there is a real fine line between 'providing data', and some not-to-be-named [self confessed] Fanboy complaining that 'providing data' that members specifically ask for, is a breach of forum policy, and an attempt at soft-advertising a product."

Don't spoil a good Information thread by taking cheap shots.

AFN has Very Hard LED Rules because of the flaming and trolling LED Talk attracts.
Don't go Proving us Right

This thread has received Reported Posts.

 

[A4]

I would be REALLY interested to see a PAR measurement test, across multiple points, at various set heights, across multiple, commonly used light sources.

i.e. standardised measurement grid [20cm intervals?], in a standard sized tent [120 x 120 ?], at say 0.5m, 1.0m, and 1.5m from light source, for HPS vs MH vs LED [insert manufacturer here] vs CFL ?

What would that give us?
A 49 point data set per height x 3 height measurements?
Should be enough to build an accurate representative model of true PAR values on offer.

Which would be more accurate to compare?
Total watts claimed?
e.g. buy this new [insert manufacturer name] XXX watt Super Duper light

Total comparative watts claimed?
e.g this new Super Duper light has the equivalent power to God shitting a supernova, after snorting bath salts

Or actual watts drawn?
[self-explanatory]

Growers House does these tests. You are correct though, I haven't seen many manufacturers doing it. They test at 18, 24 and 36 I believe and test at given points inside the square. 1x1, 2x2 and so on up to 5x5 with PAR readings displayed for every point. in my very limited knowledge it seems to be an excellent test, comparatively speaking.

From those tests and looking at PAR data, comparing to HPS, and taking into account the actual current being used, LED vs HPS is about the same when comparing wattage used to wattage used. In other words, it takes about the same amount of wattage in LED produce the same PAR output as HPS. The defining difference is heat and cost.

I have wanted to swap to LED for a couple of years now but I have yet to find one that truly replicates 1000W HPS. To boot, I have yet to find people that are honest enough to discuss it without starting a BS flame war on my light works better than yours BS.

So I suppose my question to you guys is, do you see anything in the near future that can do this? I see a lot of people growing top notch plants with small LED like GN but those are small plants and the intensity doesn't have to be there. In many cases they are only growing one or two plants as well. I grow photoperiods that are 6-7 foot tall and my HPS will cover 6-8 of those plants depending on average spead of the branches. So not only do I need spread I need intensity as well.

 

[GoAuto6]

 

[Corgy]

Corgy, whats a controlled atmosphere storage - some kind of growth chamber? And what did you see?

Controlled Atmosphere (CA) is for storage of live produce, everything from Apples to Blueberries to cut flowers. By reducing O2 and increasing CO2, the shelflife is prolonged due to a reduction in respiration. What we saw was the same batches, or container loads, of fruits/vegetables/ornamentals would behave differently under the same conditions, and trying to pinpoint why proved very elusive. It works just fine and has been used for donkeys years.......ever wondered how it is that many fruits is available year round, even though harvesting only takes place twice a year, Southern and Northern hemisphere respectably.

What I meant to say, was that pinpointing WHY something works (or doesn't) is not always straightforward, but what is always certain is that it is hugely expensive and required a lot of resources to find scientific answers, just like the finer points of LED light does.

 

[Mike-groglo]

Can I just say...

an LED light doesn't quite work the same way output wise...

for example...a 600W HPS (or any other HiD) will use around 608 - 630W of power, an LED output of 600W is a DC power measurement, probably the single most confusing measurement in the entire world...

You take 240VAC and turn it into DC, that is the point at which you measure your draw from the wall...so for this example, lets take a reasonably efficient transformer and LED and shove 300W up its backside from the wall and we should theoretically get somewhere between 450 - 750W of DC power out of the front end...dependent upon many factors, BUT overall that's the factor, and unless you're pretty good with a clamp meter and access to the innards, you probably will never know what your light is actually drawing at both sides unless you ask a manufacturer to tell you...and some of them won't give you actual figures...

M

 

[Mike-groglo]

So I suppose my question to you guys is, do you see anything in the near future that can do this? I see a lot of people growing top notch plants with small LED like GN but those are small plants and the intensity doesn't have to be there. In many cases they are only growing one or two plants as well. I grow photoperiods that are 6-7 foot tall and my HPS will cover 6-8 of those plants depending on average spread of the branches. So not only do I need spread I need intensity as well.

Intensity is going to come from the LED, the power and the wavelengths used...but visual intensity and PAR intensity are very different things...so a PAR intensity of 215umols SQ/m sec is what most sceince bods say is optimal, what it "looks" like is subjective.

M

 

[A4]

Can I just say...

an LED light doesn't quite work the same way output wise...

for example...a 600W HPS (or any other HiD) will use around 608 - 630W of power, an LED output of 600W is a DC power measurement, probably the single most confusing measurement in the entire world...

You take 240VAC and turn it into DC, that is the point at which you measure your draw from the wall...so for this example, lets take a reasonably efficient transformer and LED and shove 300W up its backside from the wall and we should theoretically get somewhere between 450 - 750W of DC power out of the front end...dependent upon many factors, BUT overall that's the factor, and unless you're pretty good with a clamp meter and access to the innards, you probably will never know what your light is actually drawing at both sides unless you ask a manufacturer to tell you...and some of them won't give you actual figures...

M

I understand what you are saying, I have been a controls electrician for just over 20 years and am working on my electrical engineering degree as well. Not being boastful, just providing background so you understand I am not making uninformed statements.

My statement wasn't referring to output. DC Output, while important in the grand scheme of design is absolutely unimportant when referring to watt usage. Yes, a more complex and efficient driver can make better use of the AC being supplied but at the end of the day there are only two factors important to growers. 1) Wattage amount being used 2) PAR being generated on the opposite end.

When I look at the tests and compare true AC wattage being used and the PAR values at specific dimensions on the theoretical plane, then LED and HPS is almost the same in a few cases and in many cases, LED is still struggling. Let me see if I can bring some data into the discussion and maybe you, or anyone else, can explain it to a point I can understand. I post a follow up shortly.

 

[Mike-groglo]

Hi A4

I would indeed agree that many LED products will struggle watt for watt against the way the HPS produces light...as you are no doubt aware, a source like HPS is capable of being bounced significantly, certainly in the visual spectrum...

LED does not like being bounced around, inverse law works AGAINST LED technology which is an indirect source at best, however penetrative wise a good optical lens and a good high power chip will be significantly better than an HPS if it is handled correctly. We all know the HPS spectrum is "wrong" but in terms of sheer light output and the driving of photosynthesis it works, it's tried, tested, and people KNOW how to use it...

M

 

[A4]

So, if you look at the picture below, I pasted the PAR results from three different lights, one that is basically set up like mine with an OG hood, a digi ballast and 600W bulb with the exception mine if 1000W. The second is an Solar Storm 800 and third is the Black Dog 800. Both the LED lights are some of the best on the market in my opinion and rightfully so, cost appropriately. What my point previously was, the 600W HID is drawing ~600W AC, the Solar Storm is drawing ~720W and the Black Dog is drawing ~730. So even given the LED are drawing approx. 100W more they are relatively the same throughout the plane. This is comparing them to a 600W HID, I have yet to see anyone that can come close to replicating a 1000W, which is what Solar Storm claims to do but the numbers don't lie.

So, back to my original point, in order for LED to compete with HID, they have to be using the same amount of energy(electricity) right now. I don't know how that will be in the future, as I am sure technology will get better but for the time being I can't see the advantage other than the heat factor?

BTW, all of this information is at Grower House dot com if anyone would like to see it for themselves