250 watt or 400 watt hps and heat issues ???

ok i got an area 2x3 i currently use to grow 4 small plants with cfls. I have have be reluctant to use a 400 watt hps because of the heat issues But now i believe that a 250 watt hps would be adequate for my size room. Then my question is will the 250 watt pose the same heat issues as a 400 watt ? I am hoping that with the 250 watt a simple fan at the bottom with my carbon fan pulling the air up and out would help keep temps down

Cant see how a 2x3 can be an issue with a 400w hps there is hardly any heat generated by them how tall is yr closet ?? Wot size extraction do u av pullin out ya room even a 4 inch could keep a 400 cool ?

i dont understand how you can say there is no heat generated by a 400 watt hps...i had one in a closet years ago and that closet got smoking hot

superiordude said:

i dont understand how you can say there is no heat generated by a 400 watt hps...i had one in a closet years ago and that closet got smoking hot

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I agree.

I'm a 400w user in a closet that measure 3.2x7x8ft. My active growing area is 3.2x3.2.

I actually use a 480m3/h - 250CFM, 6" fan on a speed controller.

The 6" fan is more than enough during winter but runs flat out during summer running to keep my passive intake grow room cool enough.

Realistically if you have a decent 5" or 6" exhaust fan then you should be ok as long as your ballast doesn't live inside your grow room.

Be prepared though if you choose the 400w to have to go out and get a cooltube.


Ultimately whether the 400w will work is down to ambient air temp, CFM of your fan, intake air temp and whether you will be air cooling your light.

I used to run a 600w in my closet grow, air cooled with independant 400CFM/660m3h fan that just air cooled the light with a second fan as exhaust and filter.

Even during summer my grow room would reach 29C about 84F with all my fans running on full.





J

thanks for the info but im not sure who you agree with....lol....would my carbon filter fan act as an exhaust fan ???

I have a 600 watt in a 3x3x6.5 tent in the closet. I run it from 6p-6a, since I'm home. My temps rarely get above 74, because my house is damn cold. However, over the summer when i bought it, It was cruising at 85+. I think you're gonna be fine. And when I'm done, I'm gonna sell my light and buy a 400 watt.

You should be fine with 1, and that fan setup should be enough to keep the heat down. It'll probably working non stop to keep the temp down cause 400w do put out some heat. Good Luck.

Nursemajor said:

I have a 600 watt in a 3x3x6.5 tent in the closet. I run it from 6p-6a, since I'm home. My temps rarely get above 74, because my house is damn cold. However, over the summer when i bought it, It was cruising at 85+. I think you're gonna be fine. And when I'm done, I'm gonna sell my light and buy a 400 watt.

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I'm in a 39x39x79 tent with a 600 cooltube. I would keep the 600 instead of selling it.

superiordude said:

thanks for the info but im not sure who you agree with....lol....would my carbon filter fan act as an exhaust fan ???

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I was agreeing with you about the heat generated by a 400.


As for your filter and fan, it depends entirely on what amount of air your fan can move.



J

1 what ??? 250 or 400

1 400 should be good with a good fan. 1 250 should be even cooler since it puts off less heat because less wattage.

I had a 400 in a 19" x 24" x 60" steel cab, vertical hung with no hood, one 4" axial fan drawing out through he top, passive intakes in a 55F basement. I never saw that go above 72F, I actually had trouble keeping the temps up where i needed, if i had put a radiant barrier or insulation in it would have probably been ideal, or a 600 would have brought temps up and given me more light