250 watt heat issues, help needed

Hey all, this is my first grow as well as my first attempt at a grow room. My only option is a small closet (6x3x4') in my basement. The closet is full of cracks and holes. I thought that this would help eliminate heat issues but not so much. Im using a 250 watt MH/HPS lamp for 2 plants. I have 3 small desktop type fans for circulation and my light is about 2.5 ft away from the tops. Seems like quite a distance but if I go any lower Im fighting to keep it below 87F. Placing a fan up top to vent the hot air proved to be worthless. Any advice would be greatly appreciated. Also the plant in the pic is 10 days old using the current setup. Thanks y'all.

Veeners5 said:

Hey all, this is my first grow as well as my first attempt at a grow room. My only option is a small closet (6x3x4') in my basement. The closet is full of cracks and holes. I thought that this would help eliminate heat issues but not so much. Im using a 250 watt MH/HPS lamp for 2 plants. I have 3 small desktop type fans for circulation and my light is about 2.5 ft away from the tops. Seems like quite a distance but if I go any lower Im fighting to keep it below 87F. Placing a fan up top to vent the hot air proved to be worthless. Any advice would be greatly appreciated. Also the plant in the pic is 10 days old using the current setup. Thanks y'all.

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Veeners5...what is your living situation? Housemates, parents, nosy next door neighbors?

If you have the time and resources, I would strongly reccommend building an exhaust system for your growing. You can build a very simple one out of dryer tubing and some strong fans, pretty much a similar concept involved with the exhaust fan of a bathroom.

Otherwise, it would be very beneficial to maybe get a large box fan or two and have one point toward the grow, and one away from the grow. Keep in mind that radiant temperature is different than air temperature. Make sure that your temperature reading device isn't placed directly in light of your MH/HPS bulb as it will read hotter than it actually is.

Especially this young in age, the plant is not very vigorous, so if the heat is too high it could easily damage and kill the plant, but you are probably looking at stunted growth as opposed to death.

Take a look at the RIU FAQ page on ventilation:

https://www.rollitup.org/view.php?pg=faq&cmd=category&id=67

is hard to belive that u having heat problems with only 250 watt but anyways read the faq in this sit is really helpfull and try spraying the plants whit some mineral water(sparkli water) it act as co2 and helps keeping the temp down

This is also a closet. 3'x3'x5'
250W hps
With lights on and the door open 3"
Fans keep the room temps 76-78
Thermometer on the outer limits of the grow space reads anywhere from 77-86
Plants suffer no heat issues, other than bleaching of leaves if the lights to close.

16" fan pulling in cooler air from outside the closet not pictured.

Thanks for the input guys, I appreciate it. I own my house with my wife and young kids (under 5, all 3 of em'). No nosy neighbors. I only have to worry about smell (b/c of guests). There are so many holes and gaps in this closet it seems futile to try to vent it with a passive intake, so I can shut the door. I put som fans blowing in and got temps down to about 79-82F so thats not too bad. Thanks for all the help dudes.

Veeners5 said:

Thanks for the input guys, I appreciate it. I own my house with my wife and young kids (under 5, all 3 of em'). No nosy neighbors. I only have to worry about smell (b/c of guests). There are so many holes and gaps in this closet it seems futile to try to vent it with a passive intake, so I can shut the door. I put som fans blowing in and got temps down to about 79-82F so thats not too bad. Thanks for all the help dudes.

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Stupid idea but have you tried to aim the fan directly at the bulb? This could lower your overall temps in the room cuz the light would be running cooler. Maybe...maybe not...worth a try

Yeah, Im doing that now. I have a small oscillating fan blowing above the plants and a large oscillating fan a little further away blowing on the plants. I have temps now about 79F with the thermometer directly under the light. Going to move that now.

be sure that the bulb is ok ur using, if its old or your not sure about it buy a new one. Dont try to grow with old bulbs i´ve wasted enough time and pulled my hair wondering what i´m doing wrong until i figured this out :/
if you can have a open door to the next room from the growroom open and maybe open window there or try to make some airflow, need fresh air if you want to control the heat. '(doesent matter how many fans you have if your blowing the same hot air over and over )
hope there something usefull

Awesome, thanks guys, I've got under control now. The whole time it was \b/c of the therm. sitting under the light. My temps r down to 75-79F now.