Effiency race... is it necessary ?

S

speedyganga

Well-Known Member
Hi everyone,

I ressently read this article and some others on the Leaf Surface Temperature comparaison between LED burble vs white, LED vs neon and LED vs HPS.

I was shooting for 75F in my grow room when using HPS, and when I made the switch to Led, and then COB, I kept my habits. After reading this article, I started raising the Air temp to 80F and saw higher growth, so I went up to 85F by reducing a lot the extraction. So far plants respond better than at 70F and I intent to keep runing my grow at 82-85F for now on. :weed:

Now, we all sicks more efficient COB and while I feel that is great, I think we are already at the limit...
Lamp needs to heat the grow room as well as provide light.
If let say you spend high $ on a 80% efficient LED, and you need to add a low efficiency heater in the room to achieve the correct temperature and you run a huge and expensive extrcation fan, Is that still efficient ?

Because HPS output lot of IR we needed strong extraction. When room temp is at 70F the LST is actually around 83F.
With Led we can reduce the extraction to what is needed for the plant - i.e the volume of the room extracted 4-8 times per hour - and rise the room temp at 80F to achieve this ideal 83F LST.
Right now, I have a LED lamp around 55% efficient in my box, and I have sometimes difficulties to reach this 80F degrees.

So let me ask:
what is the point to pay $$ for 60% efficient LED if I need to add a heater ?
What is the point to have 60% efficient LED if plant metabolism is low in the room ?

Isn't 50% and "great spectrum" sufficient in most of our application ?
At 40% efficiency, LED are already better than HPS due to their adapted spectrum, going to 50% enable us to reduce electricity cost and extraction speed, but above that, depending on the Temperatures in your place I don't think you actually benefit of the $$ you invest.

Please guys, let's discuss this issue :)

I also think while people switch from HPS to LED, they do not use their LED to full efficiency. For 2 years now, I changed the way I water, the nutrients regimen, the room temperature etc...
We should start to talk more about these, instead of numbers and BS around LED brand. Truth is, I saw some guys doing great grow under any lighting, providing they dialed in the environment...
:fire::fire: -----------LET'S TALK GROWING----------- under LED :fire::fire:


peace :peace:
 
gelgora

gelgora

Active Member
Different strains like different temps. Some boom at 75 which can be hard to get to with hps.
 
CobKits

CobKits

Well-Known Member
speedyganga said:
what is the point to pay $$ for 60% efficient LED if I need to add a heater ?
Click to expand...
none but it sure would be cooler to add more lights, a co2 burner, dehumidifier, reduce your ventilation to conserve bottled CO2, etc etc.assuming youre not at the limit of light saturation, you can either add more light than you had before or make your growing area larger. LEDs are more efficient but 1000W in a room is still 1000W of overall heat. youre just getting a lot more photons for your same 1000W.

while some people need supplemental heat, its the exception rather than the rule and usually only seasonal. it is currently 59 degrees in my house right now (midnight, <20 degrees outside, house is heated by passive solar and waste garden heat.) thats pretty unusual but its extra cold tonight and it was a cloudy day today. 350 days out of the year thats not a problem

speedyganga said:
What is the point to have 60% efficient LED if plant metabolism is low in the room ?
Click to expand...
if your plant metabolism is low its not your LEDs fault. if youre in a cold climate get a tent and put your exhaust on a temp/humistat and you prob wont need more than a reservoir heater. right now my dehuey is inside my tent so i just need a tempstat on the fan

speedyganga said:
At 40% efficiency, LED are already better than HPS due to their adapted spectrum, going to 50% enable us to reduce electricity cost and extraction speed, but above that, depending on the Temperatures in your place I don't think you actually benefit of the $$ you invest.
Click to expand...
sure you do, but its a calcualted return. youre adding variables to that assuming the LEDs are going to prevent the grower from maintaining the right environment which isnt necessarily the case. you could also argue LED efficiency is offset by yield loss to nutrient deficiencies seen under LEDs but again thats the grower failing to adapt to his enviroment
 
S

speedyganga

Well-Known Member
@gelgora
Interesting, I grow sativa dom (C99 and Jack), they seems to have better response above 80F - again under LED. What about your strains?
What you said seems to show you didn't fully understand my point: "75F" means nothing, we need to talk about SLT. If you meant they grow better at 75F under HPS, then you need 80F at least under COB...

@CobKits
I live in Europe, sumer is hot, winter is cold where I am... But generally speaking I will grow in the day in winter, and at night in summer. I grow in my own flat as it is just a personal grow. So generally speaking I got 68F to 73F in the flat all year (heater on in winter / grow at night in sumer). Also CO2 is already around 900ppm because we live close. don't want the extra hassle to run 1500ppm.
Inside the box, if I want 85F I need to reduce the extraction fan a lot... then humidity rise... Considering box tissue exchange heat but no humidity, you need to have a light that output some good heat.

I can see how the deshumidifier could be beneficial to add heat and reduce air exchange due to RH in control, extraction still seems easier to use and consume less energy.

I see it in terms of Maths, I need to solve a system where T=80F to 85F, H=40 to 50%, their are different ways to do it, But at the end we want the cheapest investment and bill on a let's say 5years basis.
You suggest I should add a dehumidifer, so more $, a very efficient LED so more $, so I will save a tiny bit $ on extraction bill and investment. I am not sure the system is more efficient at all...

It seems growing under LED needs to be at higher Temps, it reduces extraction needs, once the extraction is so low that it match the plant needs for fresh Co2, you have the good heat/light ratio in your lamp. This ratio gives efficiency.
Maybe it is 80% efficiency, Idk, that is the purpose of the thread.
 
CobKits

CobKits

Well-Known Member
speedyganga said:
You suggest I should add a dehumidifer, so more $, a very efficient LED so more $, so I will save a tiny bit $ on extraction bill and investment. I am not sure the system is more efficient at all...
Click to expand...
definitely i think we can agree that you need to look at the whole system, and every one is different. generally heat is the enemy, esp in large grows. in this case when we look at overall system efficiency LED wins because of more efficient light production as well as reduction in climate control energy

in your case in a small grow, it wont be as pronounced, and id certainly say if youre adding heat thats going to skew it back towards your original HID economics

i personally think that all things being equal the better spectrum alone is worth it as the product seems to be higher quality under LED in my experience (both purple and white LED in this case)
 
G

goofy81

Well-Known Member
Different seasons/environment/location.. different opinions

My area hit 107f+ today!
Night time temps are 82c!

For me, efficiency is king! power prices here are 35c a kw!

All my LED's are running at 50w, Had to dim all to ~35w and my room still hitting 87f !!!
Its like this for like 3-5 days straight! then its going to cool down to the 90's daytime temp thank god!

Check it out ! You can see exactly when my lights turn on (the leds do heat up the room! and when my wet wall waterpump kicks in too)
heatwave.jpg
 
S

speedyganga

Well-Known Member
CobKits said:
definitely i think we can agree that you need to look at the whole system, and every one is different. generally heat is the enemy, esp in large grows. in this case when we look at overall system efficiency LED wins because of more efficient light production as well as reduction in climate control energy

in your case in a small grow, it wont be as pronounced, and id certainly say if youre adding heat thats going to skew it back towards your original HID economics

i personally think that all things being equal the better spectrum alone is worth it as the product seems to be higher quality under LED in my experience (both purple and white LED in this case)
Click to expand...
So I guess I am good right now @ 55%eff with my set up and parameters, I won't upgrade too higher efficiency or I will need to slow even more my fans.

I agree totally, spectrum makes such a difference between HPS and LED... maybe also the fact that there is no IR nor real UV helps with preserving terpenes.

I am a believer in Pink... I made my own High bay led, with osram oslon ssl80 topbin and luminux for UV led.
I got 730:660:630:6500K:420 nm on my custom MPCB.
So far plants just super love it, and I can see verywell in the grow, no problem of purple vision.

goofy81 said:
Different seasons/environment/location.. different opinions

My area hit 107f+ today!
Night time temps are 82c!

For me, efficiency is king! power prices here are 35c a kw!

All my LED's are running at 50w, Had to dim all to ~35w and my room still hitting 87f !!!
Its like this for like 3-5 days straight! then its going to cool down to the 90's daytime temp thank god!

Check it out ! You can see exactly when my lights turn on (the leds do heat up the room! and when my wet wall waterpump kicks in too)
View attachment 3869497
Click to expand...
Hell yeah ! I can see why efficiency is King in your case bro. I guess growing under HPS was a real challenge before...
No AC i suppose ?


>> All in all efficiency of the Led lamp depends of the setup locations basically.
People living in hot area should pay extra $ for higher efficiency, but it is not the best choice for the one growing in colder climate.
 
G

goofy81

Well-Known Member
I don't use a.c.. I have a 14,000btu in the room but it does absolutely nothing! I use a swamp cooler that has a fan as powerful as my outtake fan. However my rooms always 70-80% rh because of this.

When I first started growing with HPS , I never had ac and my room would reach 100-115 every time lights went on. I never got over .72 gpw because of this.
Also, it makes me question people when they say things like the plant can't survive above 90-95 etc..
 
S

speedyganga

Well-Known Member
In my experience, the ideal parameters with led is low RH and high T°, it helps a lot transpiration and makes the plants quicker. First time with led was not good due to high RH and low temp, same grow in summer gave me a much better harvest, that 's how I strating looking for ideal params for led and Leaf Surf. Temp.
 
sixstring2112

sixstring2112

Well-Known Member
tent grows are going to see higher humidity in general.you can move air through the tent to keep r/h in check with something as simple as a small pc fan which uses very little power.fresh air will control r/h without added heat we see from dehumidifiers,plus those things suck down power like a 3 dollar hooker.but i experience the opposite right now,its cold outside today( 5 f ) and my rooms are sitting at about 20% rh because cold air is usually dryer air.plants grow fine in this condition,sure cloning can be a lil harder to do but i still manage to root cuts in open solo cups. @goofy81 i had a a/c failure 2 summers ago and my rooms hit 135f and were prob close to that temp for a large part of that 12 hour cycle,my plants were fine.thirsty as hell but they did fine.i was shocked it didnt fry the whole crop.that was back when i used co2 and when the system went down im sure r/h was around 99% lol.
 
V

VegasWinner

Well-Known Member
speedyganga said:
Hi everyone,

I ressently read this article and some others on the Leaf Surface Temperature comparaison between LED burble vs white, LED vs neon and LED vs HPS.

I was shooting for 75F in my grow room when using HPS, and when I made the switch to Led, and then COB, I kept my habits. After reading this article, I started raising the Air temp to 80F and saw higher growth, so I went up to 85F by reducing a lot the extraction. So far plants respond better than at 70F and I intent to keep runing my grow at 82-85F for now on. :weed:

Now, we all sicks more efficient COB and while I feel that is great, I think we are already at the limit...
Lamp needs to heat the grow room as well as provide light.
If let say you spend high $ on a 80% efficient LED, and you need to add a low efficiency heater in the room to achieve the correct temperature and you run a huge and expensive extrcation fan, Is that still efficient ?

Because HPS output lot of IR we needed strong extraction. When room temp is at 70F the LST is actually around 83F.
With Led we can reduce the extraction to what is needed for the plant - i.e the volume of the room extracted 4-8 times per hour - and rise the room temp at 80F to achieve this ideal 83F LST.
Right now, I have a LED lamp around 55% efficient in my box, and I have sometimes difficulties to reach this 80F degrees.

So let me ask:
what is the point to pay $$ for 60% efficient LED if I need to add a heater ?
What is the point to have 60% efficient LED if plant metabolism is low in the room ?

Isn't 50% and "great spectrum" sufficient in most of our application ?
At 40% efficiency, LED are already better than HPS due to their adapted spectrum, going to 50% enable us to reduce electricity cost and extraction speed, but above that, depending on the Temperatures in your place I don't think you actually benefit of the $$ you invest.

Please guys, let's discuss this issue :)

I also think while people switch from HPS to LED, they do not use their LED to full efficiency. For 2 years now, I changed the way I water, the nutrients regimen, the room temperature etc...
We should start to talk more about these, instead of numbers and BS around LED brand. Truth is, I saw some guys doing great grow under any lighting, providing they dialed in the environment...
:fire::fire: -----------LET'S TALK GROWING----------- under LED :fire::fire:


peace :peace:
Click to expand...
Recycle your exhaust and you may not need a heater.
 
frica

frica

Well-Known Member
Depends on the area you're in.

Also as a poster above has implied, use a weaker exhaust fan.
 
M

MezRoGi

Member
Agreed, good observations.

Just saw another guy minutes ago, on another forum, using a heater with his new super expensive led setup ..
... just rolled my eyes to the sky ...

I personally :
- try to keep daytime temperatures equalor above 24°c / 75°f.
- went from 1200~1500 m3/h for a 4x8 (120x240) dual 600W HPS's to 530m3/hour for the same 4'x8' + an additional 2'x4', and it's dimmed to 50% in winter (!)

So less than half the exhaust with 25% more space ... that's a massive change (and electricity gain).
Your limiting factor becomes renewing air, rather than extracting heat.

Make your calculations, personally I try to not go under 1 air change per minute. ( ie 128cfm min for a 4x8(x4) )

I also added an extra 4x4 in the same room, that 4x4 runs during daytime, the others have their "day" at night. This keeps a good temperature balance at all times, and all year round.

Happy growing RIU
 
Last edited:
OneHitDone

OneHitDone

Well-Known Member
CobKits said:
definitely i think we can agree that you need to look at the whole system, and every one is different. generally heat is the enemy, esp in large grows. in this case when we look at overall system efficiency LED wins because of more efficient light production as well as reduction in climate control energy

in your case in a small grow, it wont be as pronounced, and id certainly say if youre adding heat thats going to skew it back towards your original HID economics

i personally think that all things being equal the better spectrum alone is worth it as the product seems to be higher quality under LED in my experience (both purple and white LED in this case)
Click to expand...
Someone that is smart as fuck needs to put together a zone based grow equipment guide. Your local climate will dictate your equipment needs.
All of this "HPS is shit, COBS" rule talk is just plain nonesense. To say HPS is too hot to use is just a false statement. I know guys running 6 DE HPS and cooling their room with nothing more than a 10" Vortex fan.
In my grow was ALL led this time of year I would probably need a heater in addition to the lighting (efficient?)
Bottom line is Climate Control does not only mean "Cooling". Temps need to be moved both ways depending on circumstances
 
S

speedyganga

Well-Known Member
MezRoGi said:
Agreed, good observations.

Just saw another guy minutes ago, on another forum, using a heater with his new super expensive led setup ..
... just rolled my eyes to the sky ...

I personally :
- try to keep daytime temperatures equalor above 24°c / 75°f.
- went from 1200~1500 m3/h for a 4x8 (120x240) dual 600W HPS's to 530m3/hour for the same 4'x8' + an additional 2'x4', and it's dimmed to 50% in winter (!)

So less than half the exhaust with 25% more space ... that's a massive change (and electricity gain).
Your limiting factor becomes renewing air, rather than extracting heat.

Make your calculations, personally I try to not go under 1 air change per minute. ( ie 128cfm min for a 4x8(x4) )

I also added an extra 4x4 in the same room, that 4x4 runs during daytime, the others have their "day" at night. This keeps a good temperature balance at all times, and all year round.

Happy growing RIU
Click to expand...
Well I guess we just sa the exact same thing, limiting factor at some point does not come from light efficiency any more. We don't need 65% efficient LED in every situation.

I suggest you try to increase the Temp to 80F if growing under COB, you will see they will start to grow much quicker... At least for my strains. I even go up to 85F and it seems even better, they drink, eat and grow more.

OneHitDone said:
Someone that is smart as fuck needs to put together a zone based grow equipment guide. Your local climate will dictate your equipment needs.
All of this "HPS is shit, COBS" rule talk is just plain nonesense. To say HPS is too hot to use is just a false statement. I know guys running 6 DE HPS and cooling their room with nothing more than a 10" Vortex fan.
In my grow was ALL led this time of year I would probably need a heater in addition to the lighting (efficient?)
Bottom line is Climate Control does not only mean "Cooling". Temps need to be moved both ways depending on circumstances
Click to expand...
So true !
Still 40% efficient LED would be much better than HPS, because the spectrum quality brings you better harvest and quality, and repartition is better too.
 
ChaosHunter

ChaosHunter

Well-Known Member
In the summer I imagine there will be a lot of "Heat" post and people dealing with AC units. Factor in the bulb change cost of HID too. I'm new to the COB game but finding its more easy to keep atmospheric conditions with a cooler running light.
 
tstick

tstick

Well-Known Member
Most LED lights have dimmers. And, if you use the dimmer, then there really isn't any "pedestrian" way to calculate what kind of efficiency the light is putting out because the dimmer changes the efficiency. How much does it change the efficiency? I don't have any idea. Most dimmers aren't indexed with any kind of indicators for that reading. If I dim my fixture all the way down as far as the dimmer goes, then that means that I am only using 10% of the potential output. But, if I want to gradually increase the output, then I have no idea of exactly how much power the light is using or what that is doing for the efficiency.

I would like to see a new kind of "ratcheted" dimmer that would "click" as you turned it ....and/or some kind of markings to indicate the position of the knob and what output corresponds to that position.

My light utilizes what is considered an inefficient (by this forum's standards) way of driving the emitters....but I also use the dimmer for the entire vegetation cycle -which increases the efficiency! I also use the "Gas Lantern Technique" -or "Diminished Light Schedule" for growing and that means that my inefficient light isn't on nearly as many hours throughout the entire run. How much does this improve my electrical usage? I don't have a clue! But I know it means I am using electricity more efficiently.

You can get an efficient light and use it less efficiently. You can get a less efficient light but use it more efficiently....etc. If you know how to grow, then any light will work more efficiently than the same light in the hands of someone who doesn't know what they are doing. You could have the most efficient lights in the world and still get less efficient results if, say, you don't water properly or feed the plants properly ...or have prior experience with growing a particular strain...or, if you grow clones instead of starting from seed...etc.
 
ChaosHunter

ChaosHunter

Well-Known Member
tstick said:
Most LED lights have dimmers. And, if you use the dimmer, then there really isn't any "pedestrian" way to calculate what kind of efficiency the light is putting out because the dimmer changes the efficiency. How much does it change the efficiency? I don't have any idea. Most dimmers aren't indexed with any kind of indicators for that reading. If I dim my fixture all the way down as far as the dimmer goes, then that means that I am only using 10% of the potential output. But, if I want to gradually increase the output, then I have no idea of exactly how much power the light is using or what that is doing for the efficiency.

I would like to see a new kind of "ratcheted" dimmer that would "click" as you turned it ....and/or some kind of markings to indicate the position of the knob and what output corresponds to that position.

My light utilizes what is considered an inefficient (by this forum's standards) way of driving the emitters....but I also use the dimmer for the entire vegetation cycle -which increases the efficiency! I also use the "Gas Lantern Technique" -or "Diminished Light Schedule" for growing and that means that my inefficient light isn't on nearly as many hours throughout the entire run. How much does this improve my electrical usage? I don't have a clue! But I know it means I am using electricity more efficiently.

You can get an efficient light and use it less efficiently. You can get a less efficient light but use it more efficiently....etc. If you know how to grow, then any light will work more efficiently than the same light in the hands of someone who doesn't know what they are doing. You could have the most efficient lights in the world and still get less efficient results if, say, you don't water properly or feed the plants properly ...or have prior experience with growing a particular strain...or, if you grow clones instead of starting from seed...etc.
Click to expand...
I have my driver plugged into a Kill-A-Watt and use it to dial in what I want the output to be.
 
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