HID Generating Heat?

Discussion in 'Growing Marijuana Indoors' started by forsakic, Apr 13, 2006.

  1. Hi everyone, I'm running a 250 Watt MH lamp for the first time, and I've noticed that it's generating so much heat that the reflector casing is hot to the touch and my grow closet is significantly warmer.

    Is this a reality of running HID lights? I think I'll put a fan in the closet to cool things down. Check out the picture.

  2. 250w MH will definitely throw off some heat for a small space. Where is your ballast? That throws off more heat than the light itself, hopefully yours is remote so you can place it outside of your immediate grow area.

    To cool things down you will need to exhaust the hot air out of the closet, not just blow the warm air around inside.
  3. yup. they're hot. gotta deal with it.
  4. Get a fan blowing at the light and the plant.
  5. Oh my!:eek: I hope that plant still isnt in that pot? You might wanna switch it very soon.

    But to answer your question. Build yourself an air cooled reflector. Heat will no longer be an issue with that 250 if built correctly.
  6. Hey everyone. My setup has been very haphazard because this is my first time growing and I do not have three months to commit to a veritable garden, yet. My first plant has run the gamut of "first-time grower" mistakes: poor lighting, over-watering, root cramping and being subjected to my acapella (though the CO2 helps).

    Yet in spite of all this adversity, the plant continues to persevere. Amazing.

    I obtained some metro mix soil today, and I'll be transplanting my plant into a 1.5 gallon pot. Right now, it's packed like a sardine in a cut off 2 Liter soda bottle.

    Thanks for the help, y'all. Blaze on.
  7. You might as well transplant it into a 5 gallon pot, otherwise you are just going to have to retransplant it again.

    How hot is it in your growroom?
  8. 1.5 gallon pots will be fine for vegging, but once you put them into flowering get atleast a 3 gallon pot. Transplant it ASAP that thing must be rootbound like crazy.
  9. I transplated one of my plants into a larger pot. It broke my heart to see the cramped roots at the bottom of the shameful 2 Liter pot. The plant is enjoying itself much more now. I put it into some very rich soil as well--it smelled like manure.

  10. hmm. what kind of halides are you using, looks like they are single sided.

    I use a fully enclosed Fixture with a double sided halide with the glass shielding on the reflector and the unit is still very small. use two fans and the heat is not a issue.

    single sided bulbs tend to get a lot hotter, double sided 250watt will have the output of 400watt single sided without the heat issues.

    downside is

    HQI fixture are somewhat new and expensive campared to, say HPS type setups.
  11. generally HID lamps should be hung around 3 feet away, any closer for young plants could give them heat damage.
  12. That's not true, it differs alot depending on wattage and ventilation, etc. 250w's can be as close as 8-10 inches. 1000w's can be as far away as 3 feet +. The best way to check is to put your hand where the top of the plants are, and hold it there for a little bit. If it's too hot for your hand, then move it up until your hand is comfortable under it.
  13. exactly:)
  14. I placed a couple of 6" fans in the closet today -- one intake and one exhaust. The temperature of the closet has definitely gone down, and the lamp fixture is significantly cooler.

    I think the plant is happier too.

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