LED 💡 for 4ft x 4f x 6.6ft tent

[HCMPA]

Oooohhh my....!

I can do it around €80/100 less (when the 6" carbon filter is back in stock, so I can avoid buy the combo), I have the option to pay in 3 times, what will do it a tiny bit less painful

I need to get really high for this one let's wait to Tuesday.

 

[Rocket Soul]

The LM281B+ is 165lm/w
The LM301B is 220lm/w

The 301 is about 3 umol
The 281 isn't listed, as it's not a grow light.

The question is, how can pot brand lights be saying the 281 is 2.9umol/w
We know the lm/w figure is all visible light. We know they make very little light we can't see. We know all this visible light counts towards ppf. So realistically, the umol figures are as far apart as the lm/w numbers. The 301 is a third better. It's only people other than samsung, claiming the 281 is as good.

The 281 has a distinct disadvantage. The 301 is a 0.2w package, and the 281 is a 0.5w package. Both get over driven, but the 281 has over 150% more heat to shift. These lights are tested the instant they are switched on, but internal package temperature is very important. Lights that are thermally challenged, see their output drop soon after switching on. After they were tested. This 2.9 figure, not being from samsung, is not telling us how hard it was being driven, or how hot it was. Making the figure of little use comparatively.

I have only heard of one side by side, and the 301 made 80% more green. It's a margin I can't begin to explain. The 281 did a gram per watt, and the 301 did 1.8g per watt. I think the test was bad, but that's huge.

Lm281-165l/w
301b- 220l/w
Thats not apples to apples, they are tested at nominal power which is 65mA for the 301b and 150mA for the 281b, its pushed more than twice as hard.
The real factor in here is cost; you could replace the lm301b with many 281bs (last time i checked with a china manufacturer the 301s were 8ct/diode the 281 was 1ct). If you factor in pick and place and fabrication (more diodes cost more to put on a board) you should comfortably be able to use 4 x 281s instead of one 301.
If you were to run a 281b at 16mA (1/4 of 301b nominal current) instead of 150mA you would get a very tidy efficiency increase (over 200l/w) along with low diode temps. The 281 has its place in a grow light but if you want great efficiency you need about 4times as many as the 301bs.

 

[HCMPA]

Lm281-165l/w
301b- 220l/w
Thats not apples to apples, they are tested at nominal power which is 65mA for the 301b and 150mA for the 281b, its pushed more than twice as hard.
The real factor in here is cost; you could replace the lm301b with many 281bs (last time i checked with a china manufacturer the 301s were 8ct/diode the 281 was 1ct). If you factor in pick and place and fabrication (more diodes cost more to put on a board) you should comfortably be able to use 4 x 281s instead of one 301.
If you were to run a 281b at 16mA (1/4 of 301b nominal current) instead of 150mA you would get a very tidy efficiency increase (over 200l/w) along with low diode temps. The 281 has its place in a grow light but if you want great efficiency you need about 4times as many as the 301bs.

Hi there, I have no idea about lights and numbers, so take my thoughts with a grain of salt or maybe a handful, but my point is, if you need 4x times 281 diodes to do the same as 1x 301b... then how is possible to be more efficient?

Just asking

Peace

 

[Normannen]

Hi there, I have no idea about lights and numbers, so take my thoughts with a grain of salt or maybe a handful, but my point is, if you need 4x times 281 diodes to do the same as 1x 301b... then how is possible to be more efficient?

Just asking

Peace

from my observation it has to do with light distribution, 4 diodes will cover more area than one, so basically you want to have 4 diodes of the more powerful type in the same spacial distribution in order to achieve a better efficiency, it also has to do with angle of light diffused by the single diode.
I've noticed it with my V-tac, it produces waaay more lumen and better pfddde or whatever the moles of photons per square meter are jargonised by the plebs than my mars hydro, BUT because it basically shoots an almost straight beam of light, it only covers an area of 60cm at 1m; whilst the Mars Hydro, though waaaaaaay less efficient in terms of lumen and pppddfffee (or however they are acronymised) covers easily 1m due to diode distribution allowing me to grow more plants in the same area though with slightly less dense buds, it's about tradeoff.
what I'm getting at is, as long as you have at least 1000 PFFFFDeheheheheh well distributed in your grow area with a decent RB balance and possibly a couple yellow lights thrown in you are in the Gucci zone.

 

[Ca++]

Lm281-165l/w
301b- 220l/w
Thats not apples to apples, they are tested at nominal power which is 65mA for the 301b and 150mA for the 281b, its pushed more than twice as hard.
The real factor in here is cost; you could replace the lm301b with many 281bs (last time i checked with a china manufacturer the 301s were 8ct/diode the 281 was 1ct). If you factor in pick and place and fabrication (more diodes cost more to put on a board) you should comfortably be able to use 4 x 281s instead of one 301.
If you were to run a 281b at 16mA (1/4 of 301b nominal current) instead of 150mA you would get a very tidy efficiency increase (over 200l/w) along with low diode temps. The 281 has its place in a grow light but if you want great efficiency you need about 4times as many as the 301bs.

Apples to apples? Testing at nominal power is just that.
The idea of using more diodes than necessary, to keep them in their sweet spot, works for either. In reality though, the 301 is a 0.2w device (65mA@3v) which is run at 0.5w in most lights. I have never seen a light use enough. A QB288 (288 diodes 16x18) is rated 120-140w usually. But has <60w of diodes onboard. This is typical of pot light brands, and seen with the 281 getting just as much abuse. Yes, being cheaper, you might be tempted to run them below 150mA, but that's just not profitable. They find profit in using unspecified test conditions, that are probably instantaneous at switch on, in freezing temperatures. An LM281+ is about 2.3umol/w and in a fitting you might see 2umol/w. Anything else doesn't fit the samsung test data.

When people woke up to this, there was a stage of suppliers telling us the diode count. Perhaps some still do. It's not a headline selling figure though, as people don't look at it. More diodes, is just less profit. These are snake oil sellers remember. Sticking together anything we will buy.

 

[HCMPA]

from my observation it has to do with light distribution, 4 diodes will cover more area than one, so basically you want to have 4 diodes of the more powerful type in the same spacial distribution in order to achieve a better efficiency, it also has to do with angle of light diffused by the single diode.
I've noticed it with my V-tac, it produces waaay more lumen and better pfddde or whatever the moles of photons per square meter are jargonised by the plebs than my mars hydro, BUT because it basically shoots an almost straight beam of light, it only covers an area of 60cm at 1m; whilst the Mars Hydro, though waaaaaaay less efficient in terms of lumen and pppddfffee (or however they are acronymised) covers easily 1m due to diode distribution allowing me to grow more plants in the same area though with slightly less dense buds, it's about tradeoff.
what I'm getting at is, as long as you have at least 1000 PFFFFDeheheheheh well distributed in your grow area with a decent RB balance and possibly a couple yellow lights thrown in you are in the Gucci zone.

I see, but Rocket Soul stated that 301b is 65mA and 281b is 150mA (I think we are talking about amperage), still make it even more difficult to understand to me. My limited knowledge about light, tell me that as far as light go from the center of the emission, the distance to the target grows, so the intensity @target shrink, of course, we are talking about lots of diodes placed strategically, so maybe there is the trick that I'm not getting. I'm well aware that maybe I just say some nonsense based in my zero knowledge about it all

Peace

 

[Normannen]

I see, but Rocket Soul stated that 301b is 65mA and 281b is 150mA (I think we are talking about amperage), still make it even more difficult to understand to me. My limited knowledge about light, tell me that as far as light go from the center of the emission, the distance to the target grows, so the intensity @target shrink, of course, we are talking about lots of diodes placed strategically, so maybe there is the trick that I'm not getting. I'm well aware that maybe I just say some nonsense based in my zero knowledge about it all

Peace

I think Ca++ was saying that they are run at different specs depending on manufacturer/distributor.
but it all factures in, manufacturer, specs, budget, your knowledge, how much are you willing to listen to Ca++ and Rocket Soul.

 

[Normannen]

I see, but Rocket Soul stated that 301b is 65mA and 281b is 150mA (I think we are talking about amperage), still make it even more difficult to understand to me. My limited knowledge about light, tell me that as far as light go from the center of the emission, the distance to the target grows, so the intensity @target shrink, of course, we are talking about lots of diodes placed strategically, so maybe there is the trick that I'm not getting. I'm well aware that maybe I just say some nonsense based in my zero knowledge about it all

Peace

I say, start with wahtever fits your budget and learn from it, of course try to listen to Ca++'cause the guy knows what he's going on about.

 

[HCMPA]

I say, start with wahtever fits your budget and learn from it, of course try to listen to Ca++'cause the guy knows what he's going on about.

Looks like Ca++ knows, no doubt, God bless Internet, ICMag and CA++! Otherwise, who knows what kind of LED buy to grow some plants in the safety of my home, I will fail for sure.

Peace.

 

[trixP]

Sadly, I haven't access to Rayonled's products.

Thanks for your insight!

I noticed your location afterwards !
All the popular brands make a good quality product, warranty will be the second thing you wana look at , just had one of my ac infinity fans claimed no questions asked from my local store

Things you wana think about

 

[HCMPA]

Black Friday looks more Grey Monday than actually Black Friday

 

[Ca++]

That filter wouldn't make me happy. I'm not sure I have ever seen one so short. I have to wonder the carbon bed depth. The story worsens when we look at the pressure drop that such a filter would cause, and what a mixed flow fan can handle.
I would get a cheaper tent (making sure it opens in the right places for your space) and put the savings towards a better filter.

If things are really tight, then keep in mind that people gave away 6s these days. A free light, is rarely a waste of money. You could crack on with a 6, and get LEDs next time. So you have the money for a proper fan and filter.

 

[Rocket Soul]

Apples to apples? Testing at nominal power is just that.
The idea of using more diodes than necessary, to keep them in their sweet spot, works for either. In reality though, the 301 is a 0.2w device (65mA@3v) which is run at 0.5w in most lights. I have never seen a light use enough. A QB288 (288 diodes 16x18) is rated 120-140w usually. But has <60w of diodes onboard. This is typical of pot light brands, and seen with the 281 getting just as much abuse. Yes, being cheaper, you might be tempted to run them below 150mA, but that's just not profitable. They find profit in using unspecified test conditions, that are probably instantaneous at switch on, in freezing temperatures. An LM281+ is about 2.3umol/w and in a fitting you might see 2umol/w. Anything else doesn't fit the samsung test data.

When people woke up to this, there was a stage of suppliers telling us the diode count. Perhaps some still do. It's not a headline selling figure though, as people don't look at it. More diodes, is just less profit. These are snake oil sellers remember. Sticking together anything we will buy.

All im saying is 165 vrs 220 nrs is not comparing 2 diodes under the same conditions; one is running more than twice as hard as the other and efficiency goes down as power goes up, hence not apples to apples. And if you factor in the cost of the 2 chips then you can actually get decent efficiency out of the the 281 by using more of them at lower current.

 

[Ca++]

All im saying is 165 vrs 220 nrs is not comparing 2 diodes under the same conditions; one is running more than twice as hard as the other and efficiency goes down as power goes up, hence not apples to apples. And if you factor in the cost of the 2 chips then you can actually get decent efficiency out of the the 281 by using more of them at lower current.

Maybe it's not the same conditions, maybe it is. Both are running at their design current. They are both being tested, as they are meant to be used. This seems the most relevant testing, when trying to give a lm/w figure. As neither can actually do a watt.
Edit: The 281 might do a watt actually.. it's 0.5w by design, but I bet they push it past 1w in cheap lights. As the 0.2W 301 is often run at 0.5w

I would pop up some graphs to fully nail this down, but the LM281B doesn't actually exist. I'm using the spec of the LM281B+ when I say 165lm/w. There is also the LM281B+ Pro. Now that is much better. It's 216 lm/w is very much like the 2.9umol/w claimed for the LM281B. It would be wishful thinking to presume someone offering the LM281B would be selling the LM281B+ Pro though. What we actual see more often, is the wrong spec being used. Like... the LM281B doesn't exist.
The Pro is about half the price of the 301H, and as you rightly said, can be used in spec, to beat an over driven 301. However, such nirvana couldn't be presumed, when looking at bargain basement lighting. Though a shortage of the 301s was pushing things that way for a while.

It's worth mentioning that other difference, the sulphurisation resistance of the H (horti) 301. We seem to have a lot of sulphurous sticky stuff in the air. The H is costing quite a bit more than the B, with near identical spec. Except this resistance to aging, that really might be for us. I keep paying the extra 10% or so, so I hope it's worth it

 

[Rocket Soul]

The lm301b/h: this has been brought up by some of the manf that buys directly from Samsung: its actually the exact same diode, only that the H is flux binned according to ppf/w rather than lum/w and its allways top bin. Other than that its the the exact same thing, even the coating is also on B version only that for the H they market it as something special. The H is only really a marketing ploy, getting you to pay a bit extra conoared to a top bin B.

On the 281/301: you still dont get my point: the 281 has lower specs due to several things; one being less quality diode, but the other is that those specs are based on much higher drive current; if you want a more equal comparison you need to use the specs for the 301b at 150mA rather than 65mA. No point in comparing at different wattage as this will skew the comparison.

What i did finally was a sorta bang for buck comparison: what specs you would get by using diodes of the same $ value, just to show the 281 is not an auto discard, only to demand a much higher diode count if you wanna go for them.

 

[zachrockbadenof]

. The car guys tell us there is no replacement for displacement.

yeah that used to be the case... i had a bunch of mopars.... all but one was multi carbs.. either hemi's or 6packs... the 440's i think are 7,2litres... however when at a traffic light, and in the next lane is a 2.2 or 2.5 honda/mitsui/etc.... he will eat your lunch.... sad but true.... BUT the sound of a big 8cyl. is ass-kickin against these 2.2/2.5 with their fart pipes

 

[Ca++]

yeah that used to be the case... i had a bunch of mopars.... all but one was multi carbs.. either hemi's or 6packs... the 440's i think are 7,2litres... however when at a traffic light, and in the next lane is a 2.2 or 2.5 honda/mitsui/etc.... he will eat your lunch.... sad but true.... BUT the sound of a big 8cyl. is ass-kickin against these 2.2/2.5 with their fart pipes

Yeah, you give that 2.5 a couple of bar of boost, and you have 7.5L in there. The real gain though, is the volumetric efficiency. The nasp engine may only get a good lung full, around 3000rpm. The boosted car widens that window. Where the nasp is spinning so fast, it's getting asthmatic, the boosted car is still well on song.

The answer is straight forward. You chop a supercharger into the v8s hood. Then the little Jap car decides to turn right.

Do you know the Miata is actually an American design? The regional teams were set the challenge, to combat the small rwd British sports cars, that had been dominating the market. The USA team won, but Mazda said all the alloy wishbones and things had to be stamped steel for production reasons.
So that best selling sports car of all time, is actually American. Not Japanese.

You made a gay car

 

[Ca++]

The lm301b/h: this has been brought up by some of the manf that buys directly from Samsung: its actually the exact same diode, only that the H is flux binned according to ppf/w rather than lum/w and its allways top bin. Other than that its the the exact same thing, even the coating is also on B version only that for the H they market it as something special. The H is only really a marketing ploy, getting you to pay a bit extra conoared to a top bin B.

On the 281/301: you still dont get my point: the 281 has lower specs due to several things; one being less quality diode, but the other is that those specs are based on much higher drive current; if you want a more equal comparison you need to use the specs for the 301b at 150mA rather than 65mA. No point in comparing at different wattage as this will skew the comparison.

What i did finally was a sorta bang for buck comparison: what specs you would get by using diodes of the same $ value, just to show the 281 is not an auto discard, only to demand a much higher diode count if you wanna go for them.

You can't test the 301 at 150mA, it's a 65mA device. It would be strained, and so not a fair apples2apples. What you could do, to check your maths, is run both at 65mA.

This is the LM281B+ taken from samsungs data

With no power, it makes no light. Then as you add power, the brightness increases linearly. That line is really quite straight. Indicating that running it at lower power, doesn't increase it's efficiency. If all things are equal. Here, that means the same temperature.

If this were the Pro version, then it's 50% off price, means you could fit twice as many, in the place of 301s. This is twice as many of the most common failure point. However, people over work the 301 with power approaching the 0.5w the 281 is rated at. This over works the 301, causing losses. While splitting that power between a pair of 281 devices, actually makes there job easier. So yes using twice as many 281 as 301 is better. IF the 301 was being over driven, and the 281 is the Pro. If it's the B+ then no. If it's the B, then they don't make them anymore.


I have heard manufacturers say a lot of things. 1000w lights that consume 100w, LM281B exists, and 301B is 301H. I'm not listening to them. I have no interest. I'm feeling indignant towards the whole market. This is why I can't recommend any of it. I just don't look. If I want to know about lighting, I don't ask a salesman.

 

[Safe Gardener]

Yeah, you give that 2.5 a couple of bar of boost, and you have 7.5L in there. The real gain though, is the volumetric efficiency. The nasp engine may only get a good lung full, around 3000rpm. The boosted car widens that window. Where the nasp is spinning so fast, it's getting asthmatic, the boosted car is still well on song.

The thing is none of those 2.5 come from the factory pumping out “a couple bar of boost” more commonly 1-1.5bar. Now lots and lots of people like to add a turbo to a Honda, or other 4 banger and try to say it can hang with a V8. Well maybe a little. But now let’s compare that modded Honda/ext.. to a modded V8. Any Ford Mustang that someone takes the time to turbo will walk all but the most wild 4cyl build. Same with any other V8 that is turbocharged or supercharged.

I have a 2017 Honda Civic Si that is a lot of fun to drive. It might, I stress might, be able to hang with my 2016 F150 Crew Cab 5.0 V8. It would probably be door to door up to ~100 then I’ll admit the Honda will pull on the truck. Main reasons that the truck has a 105mph cut off built into the computer.

So stock for stock there aren’t many 4 cylinder cars that are running away from V8 cars while I’ll admit there are a few. Modded the V8 car wins hands down.

Back to regularly scheduled programming.

 

[HCMPA]

That filter wouldn't make me happy. I'm not sure I have ever seen one so short. I have to wonder the carbon bed depth. The story worsens when we look at the pressure drop that such a filter would cause, and what a mixed flow fan can handle.
I would get a cheaper tent (making sure it opens in the right places for your space) and put the savings towards a better filter.

If things are really tight, then keep in mind that people gave away 6s these days. A free light, is rarely a waste of money. You could crack on with a 6, and get LEDs next time. So you have the money for a proper fan and filter.

I don't understand what you mean with "people gave away 6s these days", you mean 6" fans? Or are you talking about 6 cylinders cars? (I'm not interested in growing weed inside cars, but I know a guy which grow chickens inside cars ).

Peace