HPS heat vs led heat

Discussion in 'General Marijuana Growing' started by Kingrow1, Jul 13, 2018.


    Kingrow1 Well-Known Member

    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 :-)
    Srirachi and hotrodharley like this.

    booms111 Well-Known Member

    I'm going to throw some of my findings down since I'm a HPS vet and run quantums also. My hps grows bigger thicker buds since there 1k's. HPS rooms only run 2 degrees over ambient temps for me with 2000w of hps with ambient temps around 75f. My quantums run way less electric and grow nice buds that are respectable sized similar to 600hps but not 1k hps. The quantums need zero cooling just run in basement but if you run them in a hot ambient temp they would need cooling just like any light source. Heat and high temps cause lower quality finished product no matter what light source. Bigger yields happen with high temps since plants suck up so much more water but in this case size equals lower quality.
    Mcgician, mr. childs and Kingrow1 like this.
    Roger A. Shrubber

    Roger A. Shrubber Well-Known Member

    h.i.d. lighting produces more IR, which heats up surfaces more than the radiant heat from an led. in a sealed environment, 1 watt in equals one watt of heat, in a well ventilated area, IR makes a large difference in how easy it is to keep surfaces cool. thats why you want your room to be around 76-78 for h.i.d., and can run up to 85 for leds

    Kushash Well-Known Member

    Just to keep the facts straight.
    The 20 page thread you mention was not your thread and was not started as the discussion you mentioned.
    Here is the 1st post created by the OP.
    This is your thread and I will be respectful and move on.
    Some of what I read recently makes me think you won our little game. I find that interesting.
    Did you say something in the recent days to the tune of, it doesn't matter how they look in veg as long as they are healthy in flower? IDK something that didn't make sense but I could have it wrong.
    To bad you didn't want to play when I was up for it.
    I'm going to have a toke and add this to my watch list for entertainment value. :peace:
    coreywebster and Kingrow1 like this.

    Miyagismokes Well-Known Member

    See, here's the niggling point--
    Heat DISSIPATION is the truly key factor
    Hps DO, physically, create much more heat than LED.
    But if you're appropriately vented, no issue
    If somebody's room is too hot, the light may be the source of the heat, but the problem is ventilation.

    Kingrow1 Well-Known Member

    That thread got to cluttered, here are the scientific principles for those that wanted the science.
    Kushash likes this.

    reallybigjesusfreak Well-Known Member

    I'm not gonna say the brand buy my LED is perfect.
    Your all trolls. Lalalalalaalalla
    trust me i know science

    Kingrow1 Well-Known Member

    Forget the whole led thing if you want, just bring the science of how light heats air and were all on the same page :-)
    Roger A. Shrubber

    Roger A. Shrubber Well-Known Member

    actually, hps don't make more heat than leds, they make different heat. one watt in equals one watt worth of heat, no matter what the device is, what matters is how the heat is emitted. hps as i said above, produce a lot more IR than leds do (leds actually produce no IR) so leds don't heat up the surfaces in the room as much, the heat they emit is just radiant heat. they also use less electricity to produce the same amount of light, so they're producing less heat per photon, but not per watt

    reallybigjesusfreak Well-Known Member

    WOW you guys are SALTY TROLLS here.
    Gonna go masturbate and play video games, be back never!

    I mean, as long as your grow area is properly ventilated, does it even matter which produces more heat?

    Miyagismokes Well-Known Member

    I thought LED has a wattage equivalence rating and not a true wattage rating... Like CFLs
    At least for the advertising...
    Roger A. Shrubber

    Roger A. Shrubber Well-Known Member

    nope, thats just a manufacturers thing, good leds tell you exactly how much wattage they're using.
    one watt of electricity = 3.412 btu...makes no difference whats using it.
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    booms111 Well-Known Member

    I was told that with a hps 60% of a watt goes to heat and 40% to light and White LED is opposite at 40% heat and 60% light per watt but I don't remember where I heard or read it or if it's true but I figured it was sorta true since less white led wattage produces same as 20% more wattage of hps. Honestly I don't know though and would be nice to see real scientific evidence.
    Roger A. Shrubber

    Roger A. Shrubber Well-Known Member

    it's out there if you look for it, leds are more efficient at producing light for the same amount of wattage, but they still produce the same amount of heat. one watt in = 3.4122 btu. period. forever. but it's in a different form than the heat from an hps. a form that's easier to be extracted by a good exhaust system.
    TacoMac, PURPLEB3RRYKUSH and booms111 like this.

    boilingoil Well-Known Member

    just a few thoughts here from running HIDs and LEDs.

    Nether HIDs or LEDs can compare to the natural sunlight that these plants have been acclimated to grow in for 10's of thousands of years. Both are lacking the full spectrum usable by the plants compared to the sun.

    HIDs can get you a lot more bud but lack some in the quality department.
    LEDs give you slightly better quality but lack some in the yield department.
    Mcgician likes this.

    MichiganMedGrower Well-Known Member

    There is a difference in heat I thought.

    It’s the efficiency of the lamp that determines how much light and how much heat.

    If a lamp is 30% more efficient doesn’t it put out 30% more light and 30% less heat?

    I can run my 315 cmh in an open reflector in my 3x3. Even a 400w hps needs to be air cooled in that tent in my room to reach the same temps with the same 4” fan.

    And the 315 puts out more light and spectrum.

    Yes there is an 85 watt difference here. But not enough that I think I would need air cooling for a new 400 w cmh if it existed.
    SSGrower likes this.

    MichiganMedGrower Well-Known Member

    Additionally. My 250 watt t-5 fixture in the same tent needs the same fan and speed to cool as the 315w cmh.

    The cmh is more efficient.

    ANC Well-Known Member

    LEDs won't burn your skin off or give you cancer.
    PURPLEB3RRYKUSH and ttystikk like this.
    Roger A. Shrubber

    Roger A. Shrubber Well-Known Member

    no. efficiency only matters in how much electricity is being turned into light....that light eventually degrades into heat.
    it is a LAW of physics, you cannot destroy energy or matter, you can only convert one to the other.
    one watt of power running into any appliance, of any kind, produces 3.412 btu. not sure how many times i have to say that. if you don't believe me, google it. look it up in electrical handbooks, physics texts....been that way since we've had electricity, will be that way as long as we have electricity
    Last edited: Jul 13, 2018
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    GroErr Well-Known Member

    Technically 1w = 3.412 btu as @Roger A. Shrubber has stated several times, regardless of the tech, that's science. The practical difference comes from efficiency, some techs (hps) are horribly inefficient which means they output more heat for the amount of usable light. The most benefit from LED's though is a more practical form factor if your space isn't a perfect 4x4 or 5x5 square. e.g. if I tried to run a 1000w bulb to cover off the area I flower in with 800w of LED's (3.5 x 8') I'd get shit from the hps because it can't cover that space evenly. With multiple LED bars I can spread them and get even coverage across that space, in addition to the efficiency factor which allows me to run lower w/sq. ft. than say an inefficient hps rig. In smaller or irregular/rectangular spaces, LED's are a no brainer.

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