You can't touch a 150w led.... I promise you that
Can a light get too efficient
- Thread starter Uncle Reefer
- Start date
Depends on how hard it's driven, but I'm sure someone has done temperature readings comparing the cob and the equivalent HID.
So the difference of adding another 15w of led to my panel would mean it's temperature would increase by in excess of 25 degrees Celsius? Or did you miss the bit where I said it pulls 135w from the wall?
You're not good at this, are you...
No, its clear you don't know.
SSGrower
Well-Known Member
What you ALL are neglecting is than none of your measurements or observations are happening in an perfectly insulated cube, which is what you would need to prove and disprove the missguided thoughts on this matter.
The laws of thermodynamics dont get broken.
The laws of thermodynamics dont get broken.
You need to look at bigger picture. Its not that temperature of the room rises so much its the mass of the heatsink that heats up, this holds the energy and radiates it mack to the room over time. It is not correct to say that it does it at the same rate but more that the energy is transferred at the same rate. A bulb heats the air directly with led the heatsink heats the air, there is a lag with the heatsink having to heat up.
Uncle Reefer
Well-Known Member
This thread is getting confusing . Going forward if you agree 1w -3.4 BTU put #1w-3.4BTU on your post if not put #hellnobtu. I am losing track of who is arguing for what.
SSGrower
Well-Known Member
1w= 3.4BTU
1W=3.4BTU
I build a 1kW led fitting, what would the equivalent HID be?
Are you saying that would put out EXACTLY the same heat as the 1kW LED?
Simple questions, straight and clear answers please
Uncle Reefer
Well-Known Member
#1w-3.4BTU
This is convection vs radiant heat. Convection heats the air and Radiant heats surfaces
Convection heat is heating whatever is in direct contact, in this case, the air around the led
Radiant heat is Infrared light which doesn't heat the air, it heats what it refracts off of.
Both Led and HID have both types of heat but
Leds have far less radiant heat than hids, therefore they heat the air more, HID's heat surfaces more
an HPS room should run at 76 air temp but the plant temps at the canopy will get up into the 90s
an led room can run much warmer 82 degrees and the plant canopy will be in the mid 80's
But in each room, if there is 1000w s then there is the same amount of BTU's in each room
However, the LED side will have an easier time cooling because AC is more efficient at 82 (led)degrees than 76 degrees (hid)
This is convection vs radiant heat. Convection heats the air and Radiant heats surfaces
Convection heat is heating whatever is in direct contact, in this case, the air around the led
Radiant heat is Infrared light which doesn't heat the air, it heats what it refracts off of.
Both Led and HID have both types of heat but
Leds have far less radiant heat than hids, therefore they heat the air more, HID's heat surfaces more
an HPS room should run at 76 air temp but the plant temps at the canopy will get up into the 90s
an led room can run much warmer 82 degrees and the plant canopy will be in the mid 80's
But in each room, if there is 1000w s then there is the same amount of BTU's in each room
However, the LED side will have an easier time cooling because AC is more efficient at 82 (led)degrees than 76 degrees (hid)
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SSGrower
Well-Known Member
Yes
When you measure heat you must consider mass. The same mass of air will me heated up the same amount as an equivalent mass of aluminum heat sink.
Rocket Soul
Well-Known Member
I think we are sort.of making the same point but from opposite sides. Quote from wiki: "It requires less water vapor to attain high relative humidity at low temperatures; more water vapor is required to attain high relative humidity in warm or hot air."
The rain on cold days have to do with this: its easier to reach 100%RH on cold days, and 100% is the point were you start getting water droplets forming clouds etc. On hot days more water gets absorbed in the air for less increase in RH: summer rains are usually the biggest rains around here, when warm air which carries more water gets cold it gushes down. Also think hairdryer: if cold air absorbed more water why do they go to the trouble of heating the air?
Energy conversion again, LEDs produce light in a different, more intense, manner, which is why if, like I stupidly did, you run an led too close to your plant you will see evidence of "burn". Not from the heat, but because of the intensity of the light. An HDI will cook the leaves much earlier thanks to the heat.
It's where people are showing ignorance, thermodynamics is only one part of conservation of energy and if something produces more light per watt than something else then that extra energy has to come from somewhere, and in this case heat energy is reduced.
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?
NanoGadget
Well-Known Member
Gee, I guess it's good that I don't grow in a hermetically sealed room. The physics does dictate that two sealed environments with identical and constant energy input will eventually equalize to the same temperature, but in real world application I keep the same space cooler with lower fan speeds and less need for active cooling with my QB. No laws of physics are being violated, it's just easier to vent heat when almost all of it is radiating upwards off the driver/heatsink of my QB (conveniently where most people locate their extraction) versus having a large portion of it turned into IR and blasted straight onto my plants. Also, because of the lack of IR penetrating and warming the biomass, I have found that I can operate my space at higher ambient temps without the need for co2. And this is where LED wins for me and my situation. Under my QB my canopy temps, and more importantly my leaf temps, are much much closer to ambient room temps than you can achieve with HID. My led room is super duper happy with temps as high as 90f because when the room is 90 so is the canopy (within a range of 2 degrees) whereas a 90 ambient temp in an HID room means that, due to IR, the canopy will be considerably hotter.
I think so too, the joys of trying to read things here and watch the rugby, I misread.
Rocket Soul
Well-Known Member
Thermodynamics allways looks easy in theory but gets very tricky in practice.
For example, a lot of people uses heat pump style heating instead of electric radiator in order to use less energy for heating, based on 1 watt allways heat the same this should be impossible.
Also, fo those who follow GML on youtube: he recently changed the temprature in his whole room (sealed) with moving one fan and lollypoping his plants. Energy going into the room remaindd the same.
You cant destroy the energy but how its transmitted and distributed is important aswell
For example, a lot of people uses heat pump style heating instead of electric radiator in order to use less energy for heating, based on 1 watt allways heat the same this should be impossible.
Also, fo those who follow GML on youtube: he recently changed the temprature in his whole room (sealed) with moving one fan and lollypoping his plants. Energy going into the room remaindd the same.
You cant destroy the energy but how its transmitted and distributed is important aswell
Roger A. Shrubber
Well-Known Member
the photons the light emits strikes a surface, and becomes heat again....theres no way around the first law of thermo dynamics, no matter how you explain it
swedsteven
Well-Known Member
Hot spot =hid
Roger A. Shrubber
Well-Known Member
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
NanoGadget
Well-Known Member
Nice.. This went up while I was typing away. Lol. This is exactly what I have found as well.
