twista420

recently purchased some mylar and added a second fan to my grow closet (creating active air intake), took it for a test run only to find that my temps peaked at 120 (20% RH) the other night. Definately not the environment I'm looking for! It's a 2 1/2 X 3 closet with a 250w Hortilux HPS.

My temps were a little high last grow, and the plants were mildly stressed, and I was hoping the additional intake would help that problem, but I've created another with the mylar. I was wondering if it would be beneficial to switch to a CFL system, maybe 125w 6800 lumen CFL. I realize my yields would be greater with a HPS, but I don't want to put another crop through the misery of overheating.

Would the CFL cool things down a bit? thanks

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BullDozeThePJs

I dont think may here would recommend that, I run a set up just a little smaller, 22x26 inches, with 170W HPS and I found no issues with heat, I have my lights lowered to about 16" above the pots and my temp max's at the mid 80's 70% humidity directly under the light fixture and a temperature in the mid 70's the the rest of the area. maybe your fans are too small. and try focusing them more on the light fixture itself to cool the ballast down a bit.

Batting1000

we need more details! Maybe pics? is the light air cooled itself or is the whole closet being cooled with these fans? How many cfm do the fans blow? etc. Where is the ballast located?. the more dtails the more we can help.

choader

Can you fit a cool tube in your box? If so, temps will drop alot. More details would also help.

Best of luck.

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JointVenture

you may want to consider keeping the passive intake ... and increasing its size, and change the new fan to another active exhaust.

perhaps ....



jv

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twista420

yes, apologies for the lack of details. one fan is an 80 cfm duct fan, located at the peak of the cab. and the other is a small appliance fan, ultra quiet (not sure on cfm). ballast is located outside of the cab, 3 feet away on the other side of the closet. never gets hot.

thanks all for the prompt responses.

as of right now I am testing a new setup. I removed the reflector wing from the light, as I believe it is preventing the exhaust from pulling much of the air from under the reflector. We'll see. I also raised the smaller fan and focused it directly on the bulb. My next step will be to increase the size of the (now) passive intake, and see where that gets me. I'll post the results if they are successful.

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smileyjohn

Hi twista! Here I go introducing myself and at the same time throwing in

When I'm in correction mode, I think about implementing just one change at a time to be able to determine whether or not any single action might solve a problem. Moving the fan to blow directly on the bulb might provide enough relief to avoid removing your reflector.

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formerfarmer

Hi Twista, I agree with smiley john in regards to fixing one problem at a time to see it's individual differences.

On a different note, I found that creating a barrier (with plexi glass) between the HPS and the grow area will greatly reduce temperatures in the grow area. In my setup (a pc case with 70w HPS) I have a peice of plexi glass isolating the air between the glass and the top of the grow case. In addition, I have 2 fans dedicated to dealing with the light. One fan is blowing on the light about 4 inches away, the other is blowing out of the case with a carbon air scrubber. I was dealing with temp issues also. So I know how you feel. Don't give up on the HPS without trying a few things first.

-Lift3d

twista420

pleasure to meet the both of you, smileyjohn and lift3d!

I was kind of posting while I was testing the second method. I had failed to mention that I had already tried the fan-to-bulb method with the wing, which dropped the initial 120F down to about 98F/43% RH (a vast improvement the same, but not quite the right temp yet). And that was only in 2 hours or so, so thats when I decided to remove the reflector.

after removal, the temps dropped down to about 94F, so it definately was a good move, but not good enough.

so I've decided to lay off, throw my 12 germed seeds out (I was hoping to have solved the problem in time). No big deal I have about 90 left, all from the same batch of green bud so it's just a matter of when and where to start another crop. I'm also in an apartment with neighbors, and my exhaust fan is old, loud and slow. The closet is half grow and half storage, so airflow is definately my problem. Therefore, I'll be patient until I have the means for more quality construction, and proper ventilation. No need putting the girls through 4 months of torture to produce a weak crop.

Thanks for everyone's advice though, and I'll definately use all of it on my next cab construction (which hopefully wont be a closet op)!!!

peace

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choader

ventilation is usually the limiting factor in my experience

Best of luck

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