Just checking

[TheCultivist]

Greetings...a lil more help required please...

I have a 400w HPS with reflector and bal and I plan to use this to illuminate a drobe/cupboard H 1500mm x W 800mm x D 750mm. Painted matt white, no powered extraction but fan on inside, passive ducts with a lil help from dual 12cm pc fans. I think I might be pushing the 400W a bit too far, but I plan to grow indicas, and smaller x's

Please advise , also the drobe is in a garage so it will be cooler, ambiently, i think its the indoor temps that I am worried about...

So many questions, so lil time. Thanks again for your collective nous in advance...

[Guest jiffa]

if your gonna put hid lamps in a drobe with no extraction therll be dead in a week or two

you need proper extration

[SirBob]

it might be ok at a pinch if it's in a draghty garage if you have the lights on at night, but as jiffa said you do need a proper extractor fan.

I have a 400w in a cool tube with a ruck 125 (l) extracting and a 125 intake, and is still getting to 30 degrees in there.

If your serious about growing you may as well shell out for it, i've one fan for almost 4 years and it's never missed a beat from being on 24 hours a day 7 days a week! Also it saves messing about with dodgy PC fans with potentially dodgy wiring etc..

[Davey Jones]

no powered extraction but fan on inside, passive ducts with a lil help from dual 12cm pc fans.

I would bin the PC fans and get proper extraction, theres no way in this world that you will get good results without fresh air, I run a 400W MH in a drobe of similar dimensions, I have a four inch extract and a four inch intake the temps too hot with that and I have the doors open!, you will defo need a 6 inch extract and a four inch intake IMO

[snadge]

That's gonna be super hot in such a small space.

better get some extraction.

[A Puffin]

Get some active extraction or they won't do well.

When I grew in a drobe I had passive extraction by making two large holes at the top and bottom of the drobe. It only just kept temps at an ok level, and I was only using flouro tubes, not a hot lamp like an HPS.

I then changed and stupidly put a 600w HPS in there, even though there was 3 feet between lamp and plant top they were frazzled in 5 minutes :wink:

They did recover, but since then I have not grown in a drobe without good extraction.

Also, you will need to think about using a carbon filter to eliminate the smell. These filters need fans to push the air through them.

Hope this helped. Maybe you can get away without extraction, but you will have problems with heat, stagnant air, possibly mold and huge smell issues.

i.e for the risk, you will get reduced yields.

Edited August 24, 2008 by A Puffin