PURPLEB3RRYKUSH
Well-Known Member
100%
HPS heat vs led heat
- Thread starter Kingrow1
- Start date
growingforfun
Well-Known Member
The sun heats our air a lot... you know deep space is cold right? You k ow those inner planets are REALLY hot right?If hps heats up the air in grow tents by much then the sun would heat the air on the surface of our planet past habitable temperatures and we wouldn't be here cause we would all be dead.
I've had this long running argument with led folk where they think hps heats your tent far too much and leds don't. I've tried to explain the science and physical principles of heat and light which be 'Conduction, Convection and Radiation' and that air is not heated by very much whatsoever from a few hundred watts of hps in a well extracted area.
Weve had to explain how to grow just so that some can realize its not leds they need but to cool their house and environment as at certain air temps everything will struggle to grow and adding light will further compound the problem whether led or not.
A long 20 page running thread and not one answer to these and other questions but im supposedly meant to state the science for these guys out of some ill born lazy ass nature they have where they simply cant or wont google how light heats air and by how much, possibly even just the basics on how the sun heats our atmosphere.
And so it carries on, prove it, show plants or your not a grower, bet you dont even grow.... well ive proved many times that i grow just firn, recent pics have shown healthy plants under hps in the middle of a heat wave here in the UK, air temps before lights on last night were 27c in my tent.
This site use to have some with brains, now it just attracts your general dross and pretty much your opinions are lame and self centred, no wonder you need me to post pics but shut up as soon as you view those pics, small grower for some years now
Why you trollin so much lol hps will heat the air up a lot, it's not hard to manage of course... but a hps bulb is pretty similar to a room heater... filament and electricity passes through it producing heat and light.
friedguy
Well-Known Member
Watts are a measurement of electrical energy. The light produced is energy that is converted from the electrical energy. The heat generated is the energy that is converted from the electrical or light energy. Light energy that is used by the plant for photosynthesis is converted into chemical energy. All are energy. None can be destroyed, just converted to another form (electrical, heat, light, chemical, etc).
Light energy that isn't converted to another form eventually degrades into heat.
HPS produces a higher ratio of heat energy to light energy compared to LEDs. Most of this heat (IR) cannot be converted into chemical energy via photosynthesis and is reflected back into the room as heat. Most green light is reflected off the green plants and soon degrades into heat as well. LEDs, however, have significantly less IR. They can also have their light spectrum tailored to the plant by limiting most of would-be reflected light (mostly green). So, hypothetically, if an LED has 0 green light and 0 IR, and all the light is being used by the plant for photosynthesis (I know... not a perfect world... just hypothetical), then much less of that LED light is converted into heat and is instead converted into chemical energy via photosynthesis if it can be.
So yes, watts are watts, no matter the source. But it doesn't mean that all those watts will be converted into heat.
Light energy that isn't converted to another form eventually degrades into heat.
HPS produces a higher ratio of heat energy to light energy compared to LEDs. Most of this heat (IR) cannot be converted into chemical energy via photosynthesis and is reflected back into the room as heat. Most green light is reflected off the green plants and soon degrades into heat as well. LEDs, however, have significantly less IR. They can also have their light spectrum tailored to the plant by limiting most of would-be reflected light (mostly green). So, hypothetically, if an LED has 0 green light and 0 IR, and all the light is being used by the plant for photosynthesis (I know... not a perfect world... just hypothetical), then much less of that LED light is converted into heat and is instead converted into chemical energy via photosynthesis if it can be.
So yes, watts are watts, no matter the source. But it doesn't mean that all those watts will be converted into heat.
Last edited:
MichiganMedGrower
Well-Known Member
Thank you for this explanation. I thought basically the same thing and it was proven in my veg tent example.
I also understand that most of the led heat stays above the lamp this is easier to exhaust.
There are so many variables.
Miyagismokes
Well-Known Member
Plants use green, just the least efficiently.
Lucky Luke
Well-Known Member
A watt of electricity is a watt of heat.
HPS (which is not what most people use in veg) heats a gas. So the light source is hotter. This heat then radiates from the fixture, Yes even that glass in the cooled hood.
"The arc then heats up the mercury and the mercury vapor then lights, giving the lamp a bluish color. The lamp heats and the sodium is the last material to vaporize. The sodium vapor strikes an arc over 240 C. The sodium is mixed with other impurities to create a more "white" light. The mercury helps add a blue spectrum light to the pure yellow of the sodium.)"
-http://edisontechcenter.org/SodiumLamps.html#hps
HPS (which is not what most people use in veg) heats a gas. So the light source is hotter. This heat then radiates from the fixture, Yes even that glass in the cooled hood.
"The arc then heats up the mercury and the mercury vapor then lights, giving the lamp a bluish color. The lamp heats and the sodium is the last material to vaporize. The sodium vapor strikes an arc over 240 C. The sodium is mixed with other impurities to create a more "white" light. The mercury helps add a blue spectrum light to the pure yellow of the sodium.)"
-http://edisontechcenter.org/SodiumLamps.html#hps
Lucky Luke
Well-Known Member
If a HPS tube is not hot, Go and grab one with your hand. 
ttystikk
Well-Known Member
It's been covered but a couple of points to keep in mind;
- Light distribution; a point source like an HID lamp is never going to distribute light as efficiently as a group of LED lights will. The more evenly spread out they are, the more efficient they are.
- I'm sure y'all have noticed that an empty room gets hotter than a room full of plants. It is not photosynthesis (that's a couple percent at best), it's transpiration. Your plants are swamp coolers, and use that to draw nutrients up from the roots...
- ...which is why you want to run a warmer room with LED than you do with HID. LED emits a lot less infrared so to maintain good transpiration you'll want to run the room in the mid 80s.
Last edited:
Lucky Luke
Well-Known Member
Kingrow1
Well-Known Member
Running much less ir than in nature is a flaw imo and just derived from ppfd claims that are again not accurate. Without the ir transpiration is flawed and you need the extra heat to make up for the loss or that swamp cooler no work.
Led manufacturers have been upping their ir since not adding it didnt work so well
Kingrow1
Well-Known Member
Plants use green the most as cited by any scientific institute that has experimented with it, its the fundamental flaw of ppfd where by plants grow better with green red and blue than just red and blue.
Some think they grow better with no ir as well but they are fast becoming wrong
Kingrow1
Well-Known Member
Your both wrong, green light is the most absorbed and conopy studies have shown that lower leaves have way more space to absorb green as the upper canopy took a lot of the red and blue.
Stop boring me with your own personal opinion and led rubbish, there are many studies that will back what i say on google and is pretty much cited as fact and that ppfd is flawed because of this.
growingforfun
Well-Known Member
Kingrow1
Well-Known Member
No the radiation as light and ir is unaffected by the cool tube (well marginally, glass rips of 5% or somthing) but the conductive and convective heat is vented.
Im not sure why your struggling to accept these facts and keep coming up with stuff thats blatently wrong i.e. your explanation vs mine on cool tubes.
Youll see that the light and tent is still simlar in temps with or without the cool tube, thats because that conductive and convective heat is very small indeed, way less than the amount of joules needed to actually heat fast flowing air through a volume of say 1x1x2 meters.
Im a gona start trolling you if you dont start getting stuff at least half right, the info on this forum and site is bad enough without you fucking it up more
growingforfun
Well-Known Member
The highlighted part confuses me because I'm pretty sure you've been trolling pretty hardIm a gona start trolling you if you dont start getting stuff at least half right, the info on this forum and site is bad enough without you fucking it up more
Kingrow1
Well-Known Member
Fuck off you moron
Kingrow1
Well-Known Member
Why leds arent cooler, its ambients that dictate air temps always, raise ambients outside your tent and watch the thermometer rise inside your tent.
We all agree here but its not proving any point we dont already know about heat and cooling, leds would argue that they produce cooler air lolol
growingforfun
Well-Known Member
Stick an stones may break my bones, but kingrow cannot troll meFuck off you moron
growingforfun
Well-Known Member
Just try a Mars hydro dude they are da best.
Hps is junk, only Sam the cave man and other lower life forms use that outdated trash
Hps is junk, only Sam the cave man and other lower life forms use that outdated trash
Kingrow1
Well-Known Member
1. Leds suffer bad overlap and single point light source dosent meaning a more even distribution of light, i cite this as leds have been tweaking them damn lenses to try to stop this problem but physically it will never achieve the efficiency of a single light point.
2. Water is among the most efficient coolers in nature.
3. As stated in point '2.' water is one of nature most efficient coolers and transporters of heat energy, for this reason plenty of ir dosent really trouble a plant, why the sun kicks out almost half its radiation as ir. Leds just saw ppfd and eliminated what they assumed were dead spectrums, turns out they and you are wrong and with out enough ir transpiration dosent happen and photosynthesis suffers.