heat differences: 250w or 400w HPS?

[BiGGj18]

A friend of mine is starting a small closet grow in which the ventilation issues could be a problem. ventilation will be somewhat limited, so heat is a concern. He is about to purchase a light, but is unsure which one. He is sure of a HPS system, but wondered if 250 or 400 would be better. Its a small closet so he will still have plenty of lumens with a 250w, but 400 is obviously better. Our question is, how much of a heat difference will there be between the two bulbs? Is the 400 much hotter than the 250, or will there be a very small difference?

[faithless]

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From what you're describing, 400w will cause you quite big heating issues.
I downsized from a 400 to a 250, because without proper vent in a cupboard, 400w is going to be too hot.

I added fluors instead to compensate.

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[TheGreenFog]

Depends what size the room is. Even with a 250, in a small space, you will have heat issues most likely. If it is a possibility, I suggest getting a decent extraction fan and isolating your light in a 'cool tube' manner. Then you can have a strong 400 and kick ass. :) Good luck. Let us know what you do.

Be cool.

:rasta: RastafarI

TGF

[faithless]

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I have 80 watts of CFL and a 250HPS in the middle.
My closet is 29" by 41". Luckily the ceiling is high up, about 4 meters, even so, I have to have the door open, fans, and let cold air into the apartment regularly. If I closed the door, I would reach 40c probably within an hour.

Interestingly, the 4 * 23w cfl's seem to raise the temp by about one degree centigrade each, so even those ones added another 4c.

.

[frog1]

yo people help out the frog im just starting to grow inside and im looking for a seed bank that you can trust to send good seeds and not have to pay over 25 to 30$ for 10 i live in tha usa

[BiGGj18]

thanks for the quick replies guys. the closet is about 3' x 3' x 9' high (possibly a little wider/longer, but from memory this is my best guess). he cut a hole in the ceiling of the closet and is putting in a fan, which extracts into the attic. the problem with ventilation is, there is no intake. i thought maybe cutting two holes, one fan blowing cool attic air in, the other blowing out...? he is set on using a HPS, but i know how hot HPS get. Could you further explain the 'cool tube' cooling idea?

[TheGreenFog]

I have 80 watts of CFL and a 250HPS in the middle. My closet is 29" by 41". Luckily the ceiling is high up, about 4 meters, even so, I have to have the door open, fans, and let cold air into the apartment regularly. If I closed the door, I would reach 40c probably within an hour.

Interestingly, the 4 * 23w cfl's seem to raise the temp by about one degree centigrade each, so even those ones added another 4c.

Yea, you need good ventilation. Enclosed lights are the way to go. Strong fans rock, but are noisy.


yo people help out the frog im just starting to grow inside and im looking for a seed bank that you can trust to send good seeds and not have to pay over 25 to 30$ for 10 i live in tha usa

Frog? Where did you get that name from?? :o Hijacking...much? This question should not be posted here. Go try the Seeds/Strains forum. :D Get another user name too. That one's lame. lol :p You spelled frog1 wrong...hehe


thanks for the quick replies guys. the closet is about 3' x 3' x 9' high (possibly a little wider/longer, but from memory this is my best guess). he cut a hole in the ceiling of the closet and is putting in a fan, which extracts into the attic. the problem with ventilation is, there is no intake. i thought maybe cutting two holes, one fan blowing cool attic air in, the other blowing out...? he is set on using a HPS, but i know how hot HPS get. Could you further explain the 'cool tube' cooling idea?


Well, that is a decent sized room. Have you thought about dividing it in two vertically? That would be perfect for a veg (on bottom with CFLs or T5) and bloom up top since you have hole there already.

Intake...well, depends if you do that stupid idea I just typed up there ^...lol. If you only have one room...check out my thread and look how it is done in "The JOURNAL". :) That's one way. Active exhaust UP. Passive intake from bottom, through closet grate...

HPS rocks. It's the only way to go for a serious plant(s).

:rasta: RastafarI

TGF