Can a light get too efficient

[NanoGadget]

if you have two devices that use the same amount of power, in the same setting, then they will produce the same amount of heat....period.
efficiency makes absolutely no difference in the production of heat...its the amount of power going in. you may have the most efficient led in the world, but if it uses 1000 watts of power, its going to produce 3400 btu per hour. it will also produce a lot more photons than a less efficient lamp...but it will still produce 3400 btu per hour

That great in a sealed and static environment. But the way IR is absorbed by, (and thus the degree to which it heats) biomass changes the variables greatly. The ability to cool more easily with less extraction due to the way the heat is radiated, combined with the ability to run the room warmer due to a much smaller temperature variance between ambient and canopy means that I actually use less real world energy to maintain my grow.

 

[Rocket Soul]

Since we are in this discusion id like to gauge what people think about this:


As for enviroment, chip temprature be damned, but how does the temp of the heatsink affect the enviroment?


You could for example have a fixture which dissipates say 500w of heat thru a heatsink which rise in temprature say 45 degrees over ambient.


And in an identical room and fixture with only difference being that the heat sinks are larger and the 500w only raise the temp of the heatsink by 5 degrees.



All temps at steady state operation.


Same watt in but how would enviroment react in each case? I dont think the same but would like to know what people think.


And since keeping your room hot enough is important when using leds, are there cases where you actually like your leds to run hot so you dont have to put in a 2000w radiator?

 

[Fubard]

if you have two devices that use the same amount of power, in the same setting, then they will produce the same amount of heat....period.
efficiency makes absolutely no difference in the production of heat...its the amount of power going in. you may have the most efficient led in the world, but if it uses 1000 watts of power, its going to produce 3400 btu per hour. it will also produce a lot more photons than a less efficient lamp...but it will still produce 3400 btu per hour

And what equivalence would you need in HID? The same?

No, you would need more as your led is more efficient, meaning less heat for the same level of illumination.

And that is what is being ignored, as the led is converting more of that 1kW into light, meaning that heat is reduced as you cannot produce more energy than you consume.

 

[Fubard]

Since we are in this discusion id like to gauge what people think about this:


As for enviroment, chip temprature be damned, but how does the temp of the heatsink affect the enviroment?


You could for example have a fixture which dissipates say 500w of heat thru a heatsink which rise in temprature say 45 degrees over ambient.


And in an identical room and fixture with only difference being that the heat sinks are larger and the 500w only raise the temp of the heatsink by 5 degrees.



All temps at steady state operation.


Same watt in but how would enviroment react in each case? I dont think the same but would like to know what people think.


And since keeping your room hot enough is important when using leds, are there cases where you actually like your leds to run hot so you dont have to put in a 2000w radiator?

Run them hot, you reduce life expectancy. A tricky thing to balance depending on costs involved.

 

[Roger A. Shrubber]

And what equivalence would you need in HID? The same?

No, you would need more as your led is more efficient, meaning less heat for the same level of illumination.

And that is what is being ignored, as the led is converting more of that 1kW into light, meaning that heat is reduced as you cannot produce more energy than you consume.

being ignored? did i not say it would produce more photons than a less efficient lamp?

 

[SSGrower]

You are saying that a 1kW HID puts out the same number of lumens, the same number of par watts, as a 1kW led panel?

No thats awhole nuther argument that depends on what chip, bulb, power supply, etc., etc..

 

[Humple]

And what equivalence would you need in HID? The same?

No, you would need more as your led is more efficient, meaning less heat for the same level of illumination.

And that is what is being ignored, as the led is converting more of that 1kW into light, meaning that heat is reduced as you cannot produce more energy than you consume.

But that light will ultimately be converted back into heat.

 

[SSGrower]

Nice.. This went up while I was typing away. Lol. This is exactly what I have found as well.

Yes this is a very good and well worded explaination, thanks @Uncle Reefer

 

[Uncle Reefer]

Since we are in this discusion id like to gauge what people think about this:


As for enviroment, chip temprature be damned, but how does the temp of the heatsink affect the enviroment?


You could for example have a fixture which dissipates say 500w of heat thru a heatsink which rise in temprature say 45 degrees over ambient.


And in an identical room and fixture with only difference being that the heat sinks are larger and the 500w only raise the temp of the heatsink by 5 degrees.



All temps at steady state operation.


Same watt in but how would enviroment react in each case? I dont think the same but would like to know what people think.


And since keeping your room hot enough is important when using LEDs, are there cases where you actually like your leds to run hot so you don't have to put in a 2000w radiator?

The size of the heat sink will not really affect your room ,it is more about the LED's operational temp
a smaller heatsink has less area but will heat up hotter, a larger heat sink will run cooler but have a larger surface area to diffuse the heat.
THogh a cooler running led will create fractionally less convection heat and more radiant heat

 

[wietefras]

And what equivalence would you need in HID? The same?

No, you would need more as your led is more efficient, meaning less heat for the same level of illumination.

And that is what is being ignored, as the led is converting more of that 1kW into light, meaning that heat is reduced as you cannot produce more energy than you consume.

Yep there we go, clear case of goal post shifting.

Well at least that indicates that must realize that he was wrong in arguing that 1kW of leds/light produces less heat than a 1kW space heater in a closed room

 

[Fubard]

No thats awhole nuther argument that depends on what chip, bulb, power supply, etc., etc..

No, it is valid as if you produce more light per watt then you gain that by creating less heat. The heat per watt cannot be constant irrespective of the type of light as otherwise you create more energy, light plus heat, than you consume and that is what is impossible.

 

[Fubard]

But that light will ultimately be converted back into heat.

Why?

 

[Uncle Reefer]

And what equivalence would you need in HID? The same?

No, you would need more as your led is more efficient, meaning less heat for the same level of illumination.

And that is what is being ignored, as the led is converting more of that 1kW into light, meaning that heat is reduced as you cannot produce more energy than you consume.

Light is potential radiant heat
IF you had a light that created no heat, just light, and was 1000w it would still make 3400BTU's
What ever the light hit would heat up the nessesary 3400 BTU's

 

[Fubard]

Light is potential radiant heat
IF you had a light that created no heat, just light, and was 1000w it would still make 3400BTU's
What ever the light hit would heat up the nessesary 3400 BTU's

No, it isn't

 

[wietefras]

This is convection vs radiant heat.

Yes exactly, that's what I said a dozen or so posts ago.

Convection heat is much easier to extract from the room. Trouble is though, I find it's actually too easy. If I place the exhaust fan at the top of the room I can't get the temperatures up high enough. So I have move the exhaust fan to the bottom of the room. That way at least the heat from the leds gets pulled though the plants. Add in some air circulation and the heat gets spread around nicely.

 

[Fubard]

Yep there we go, clear case of goal post shifting.

Well at least that indicates that must realize that he was wrong in arguing that 1kW of leds/light produces less heat than a 1kW space heater in a closed room

Wrong, as a space heater does not convert most of that 1kW into light.

If it did, I would be worried.

 

[Roger A. Shrubber]

Why?

because thats the way thermo dynamics work. a photon contains energy. when it strikes something, part of that energy is absorbed by the object it is striking, and released as heat

 

[wietefras]

No, it isn't

Yes it is. Just take your ignorance somewhere else

 

[Uncle Reefer]

No, it isn't

And this is where we part ways in opinion
Please go do some googling you will see
Cheers
Google is light potetal radiant heat? See where that gets you

 

[Roger A. Shrubber]

Wrong, as a space heater does not convert most of that 1kW into light.

If it did, I would be worried.

if you give it enough time, the interior of the closets WILL be the same temperature. i promise. you can trust me, i don't know you well enough to lie to you.