Can a light get too efficient

Discussion in 'LED and other Lighting' started by Uncle Reefer, Feb 9, 2018.

  1.  
    Uncle Reefer

    Uncle Reefer Well-Known Member

    Hear me out, I am starting to wonder if a light can be too efficient. I am running leds at 82 degrees and I am finding myself at the upper edge of what I am comfortable with regarding humidity. I run a big ac in a sealed room. The Ac can stay on top of the heat no problem but the massive rate of transpiration it is starting to fall behind on. Is not a big deal for me as I can turn on another Dehumidifier to pick up the slack. I think I am on the razor's edge of efficient light vs needing to add dehumidifiers or more heat to activate the ac more often. What I am wondering is if the next gen of lights that are more efficient will put out the same heat but more photons, resulting in more humidity. Is it more system efficient to use less efficient lights and stay on the edge or run the better lights and add a dehumidifier or heater?

    I am pretty sure the answer is, just adds a dehuie stupid but it is an interesting thought/issue that hasn't been a problem for me before.
     
    down to.roach and OneHitDone like this.
  2.  
    vostok

    vostok Well-Known Member

    Can a light get too efficient?

    good question and even with these techno updates

    CMW/LED etc etc answer is ....

    No not yet

    please don't confuse water in air (Relative Humidity) with heat removal by AC

    Vapour-pressure deficit, or VPD, is the difference (deficit) between the amount of moisture in the air and how much moisture the air can hold when it is saturated. Once air becomes saturated, water will condense out to form clouds, dew or films of water over leaves. It is this last instance that makes VPD important for greenhouse regulation.
    https://en.wikipedia.org/wiki/Vapour-pressure_deficit
     
  3.  
    Roger A. Shrubber

    Roger A. Shrubber Well-Known Member

    i was thinking about the same thing. in my situation, it might be better to run h.i.d. in the winter and a mix of QBs and cobs in the summer. the light itself is more efficient, but it's not more efficient for your application of it. you can't just look at lighting costs, you do indeed have to add in the cost of cooling, heating, humidity control, air flow.....
     
  4.  
    Uncle Reefer

    Uncle Reefer Well-Known Member

    In my system, during the day the ac does double duty removing both heat and humidity.
    My point is as lights get more efficient and 1000w is 3400 BTU/H no matter if its one photon or a billion.
    As the number of photos increases and the BTU's stay the same, my AC works about the same... maybe a little harder with wetter air but still, forget that for my point.
    The RH will increase with better lights
     
    hybridway2 likes this.
  5.  
    ANC

    ANC Well-Known Member

    Clean the bottom of the canopy, fewer leaves lead to less humidity.

    There are two reasons a plant transpires a lot. Needing water to cool the leaves and to look for food in response to increased photosynthesis. Sometimes increasing the quantity or availability of food will reduce transpiration, as the plant finds what it is looking for.
     
  6.  
    Uncle Reefer

    Uncle Reefer Well-Known Member

    Yup I have very few unnessisary leaves and branches.
     
  7.  
    ANC

    ANC Well-Known Member

    Try and increase the feeding very gradually. Maybe do a foliar feeding as well and check how much water you are using. You can also cover the tops of your pots to reduce evaporation.
     
    mahiluana and Nugachino like this.
  8.  
    nevergoodenuf

    nevergoodenuf Well-Known Member

    I don't use the AC unless it's summer. I do use the dehumidifier to help maintain temps when it's cool. I should check which is more efficient at dehumidifying, my 12,000 btu mini-split or my 70 pint dehumidifier? They both have a max draw of [email protected]
     
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  9.  
    ANC

    ANC Well-Known Member

    The AC will probably take 20 to 30% max RH out of the air.
     
  10.  
    nevergoodenuf

    nevergoodenuf Well-Known Member

    It does have a dehu mode, but I have never used it.
     
    vostok likes this.
  11.  
    ANC

    ANC Well-Known Member

    I must say with the LEDs I am not running the AC despite it getting up to 110 outside. They probably do a bit better with more consistency. But they are not doing too badly.
     
    Roger A. Shrubber likes this.
  12.  
    JavaCo

    JavaCo Well-Known Member

    Doesn't work like that, you trade heat for efficiency. The more efficient the light the less heat it puts off. Check out the laws of thermodynamics.
     
  13.  
    wietefras

    wietefras Well-Known Member

    Can't you reuse the heat coming out the back of the AC?
     
    vostok and Uncle Reefer like this.
  14.  
    Roger A. Shrubber

    Roger A. Shrubber Well-Known Member

    no, you check out the law of thermodynamics...as stated above, 1000 watts equals about 3400 btu. period. the efficiency of leds means you need less wattage to get the same amount of photons. using less wattage means less heat. if you put a real 1000 watt led in an enclosed area, and a 1000 watt hid light in the same sized area, within an hour or two, they'll be the same temperature.
     
  15.  
    Uncle Reefer

    Uncle Reefer Well-Known Member

    you can but then you have to cool even more, but that is a good solution. THat is basically what a dehuie is
     
  16.  
    nevergoodenuf

    nevergoodenuf Well-Known Member

    I have done this test and my results were different. With minimal air movement in and out of tent and in a sealed tent (5'x5'). Don't remember the # on sealed, but a 600w HPS, once temps stopped rising (82*F). Everything the same but 950w of COB leds, it stayed at 78*. Sealed #'s were a little closer, but can't find the #'s.
     
  17.  
    Ryante55

    Ryante55 Well-Known Member

    If you have more light and less heat maybe you can replace the AC with a dehumidifier
     
  18.  
    JavaCo

    JavaCo Well-Known Member

    Lmfao got any extra of what you have been smoking.
     
  19.  
    Uncle Reefer

    Uncle Reefer Well-Known Member

    it is true a 1000w light and a 1000w heater make the same amount of heat
     
    churchhaze likes this.
  20.  
    Sour Wreck

    Sour Wreck Well-Known Member

    i know people say this. but in my 4x4 tent with a 600 hps and 220 cfm exhaust fan with passive intake, temps run between 85-90.

    in my 2nd tent with samsung f series strips, 50 real watts per strip, 16 strips, 800 watts, 125cfm exhaust, temps run 78-80.

    not even close
     
    mr. childs and whitebb2727 like this.

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