Question about need for cooling 600W HPS

[INFI Addict]

Hey guys,

I've done a load of searching around here, but wanted to ask to get black and white responses here if possible re: this subject.


I have a mate about to start an indoor grow... he spent £500 or so on a package deal, including a 1.2x1.2x2m grow tent, and a 600W HPS.

Now, here is what I need to be able to tell him.. he needs more cooling.

His package came with a 250CFM (correct term?) extractor fan, which is connected directly to a carbon filter.. that is the only ventilation he has, and he hopes to dangle a 600W HPS 70cm about 6 plants...


Now, I'll put my hands up if I'm wrong on this one, but that doesn't sound like anywhere near the cooling he will need... 600W at 70cm and no direct air cooling (like tube or hood) will fry his plants right? ?

I know that larger spaces eat more heat up, but my old grow box which was about 3x4' with an HPS of 150W, got to about 124 degree's without additional cooling... and this is 4x the power.

He thinks he doesn't need it, cos his kit is an 'all in one' kit... but wants me to query it here so he can get any extra cooling if required. True it will be cooler near the floor, but 70cm seems to close with no direct cooling.

- I think that the 250CFM fan will not be sufficient as it will use a lot of its power sucking air through the filter and isn't positioned to remove air from the bulb.
- I think that placing a stand up fan over the light isn't going to remove the necessary heat.
- I think he needs to get a cooled hood or something.


Am I barking up the wrong tree here?? I wouldn't want him to fry his plants, and he wants to get it right.


Thanks guys.


Alex

 

[bondjamesbond]

i would say do a test run for a day and see the high low temps to be sure....but of course more ventalation NEVER hurts.....of course he would be better off with a 8 in vortex 747 cfm fan in stead of a 250cfm......but i say run it for a day, see the temps, and go from there......but i would deffinatly make sure to have atleast a box fan or ocilanting fan blowing right across the the tops of the plants/bottom of the light, preferably towards the carbon filter/ exhaust fan

hope this helps

 

[INFI Addict]

yes bondjamesbond mate, cheers for the input... thats what I said to him, test if for a day, see what happens... he wants to jump into this puddle two footed, but I think it may be a deep one if he does... best to test it properly.

Thanks

 

[FAT MAT]

im hearing twice the intake as the out put. say you have 4 inch exhaust you would want to have 8 to 10 inch intake and like bond said have an ocilating fan blowing over the plants but not directly onto them.

 

[BudLove]

The other key factor in all of this is : What is the room's ambient temp? Regardless of the amount of exhaust he's using, if his ambient temps are 78, it wont matter...

BL