Much ado about heat

[Delightful]

So, me and my buddy are gonna start a grow, this will provide ample material to make some lovely hash.

However, I just cant seem to solve the heat issues. Before, I made a custom 250 watt cabinet with a 80 cfm cool tube, and a 200 cfm fan to move air out of the cabinet. Still, i had temps in the upper 80's F and 90's F.

Now, my buddy got a pre-fab grow tent thing that is about 6 feet tall, and with a 4 by 4 base. Its got a 400 watt hps. It has a cool tube, not sure of the cfm's and exhaust fans as well.

Still, the temps are about 100 F.

I have tried to read as much as i can, but cant figure out how to get the temps down.

Should I get higher cfm fans? or is there a different approach i haven't discovered?

Oh and room temp is about 78 F

[YukonBikerGuy]

The cool tube and exhaust fan vent outside of the tent? Outside of the room, building? What sort of fan do you have on the intake?

Placing the intake low and exhaust high will help the natural convection of heat to move itself right out. Run the light cycle during the night hours to help keep temps down, particularly in the summer. Some people are forced to use some kind of air conditioning to keep things cool enough. Keep balast in a remote location, they can add quite a bit of heat.

Hope that helps some, if you have any more questions, just ask. There are many talented growers who frequent the site that also have some good ideas to add.

YBG

[DNRDustin]

Is the light being cooled by a closed circuit system? Do you have air exchange in the tent? I have seen those tents and know they are well equipped for a good grow set up! In any case you shouldnt have any heat issues with a 400w in that space. I just built a veg box of roughly the same dimensions with a 1000w and 2 computer fans, it seems to do the trick. Try taking your balast out of the tent. If all else fails get Co2. I was having some serious heat (95-115 degrees outside) issues last summer, when a buddy of mine told me that Co2 would allow my trees to grow comfortably in much higher than normal temps(high 90's). It worked wonders and gave me the time to figure out and fix my cooling predicament. Good luck gettin your shit dialed in!

[johnnyballbag]

By you saying your room temps are 78, i'm assuming you mean the room the tent is in. If the tent is 22 degrees warmer, then i'd try and figure out what size fans you're using to cool the light and exchange air in the tent. If it's a decent sized room that the tent is in, it should'nt be that large of a temperature deviation, unless you have undersized fans. If that's not the case, then you can do 2 things. You could air condition the room the tent is in, assuming the fan you're using for the tents intake is enough cfm's to move that cooled air in and out of your tent fast enough. Or if you're growing hydroponically, you could use a water chiller to offset the heat problem. Let us know what you figure out.