Two venting ideas, which would keep it cooler?

Alright guys go check it.
Here's my new flower box. Running 2, 400w, air cooled HPS lights.
The box is 4 feel long, by 4 feet wide, by 55 inches tall.
I've got a 450 CFM fan for exhaust, pulling air from outside the box, through one hood, then the other, and then back out the box.
I have not yet hooked up an exhaust for the actual room itself though.

Here's my question. After looking at the pix. Would you suggest me just putting another fan in there for exhausting the actual grow room itself, and leaving my lights and venting as is? Or should I dis-connect the venting from the one end of the cool tube, AS WELL AS getting another fan to exhaust the actual room itself?

Right now temps are at 95, but like I said, that's with ZERO exhaust.

Which do YOU think would help keep the box cooler?

~Disconnect the venting on the left side of the cooltube AND add an exhaust fan?
~Or do you think it'd be better to LEAVE the ducting, and just add an exhaust fan?

Thoughts. Opinions. Suggestions.
ALL is welcome!

put a piece of folded cheese cloth over the intake of the reflector farthest from the fan and let the exhaust for the reflectors suck the hot air out of the room through both reflectors. The cheese clothe is to keep dust and debris from going into the reflectors. Or your could get a carbon filter and put it where the cheese cloth would be with some dutcing. Have it go Filter>duct>reflector>duct>reflector>duct>exhaust fan.

caseyg2007 said:

put a piece of folded cheese cloth over the intake of the reflector farthest from the fan and let the exhaust for the reflectors suck the hot air out of the room through both reflectors. The cheese clothe is to keep dust and debris from going into the reflectors. Or your could get a carbon filter and put it where the cheese cloth would be with some dutcing. Have it go Filter>duct>reflector>duct>reflector>duct>exhaust fan.

Click to expand...

Legit, thanks bro, preciate it. Finishing it all up tonight. Will post pix when she's totally completed!

NP. Thanks for the rep. Can't wait to see it completed.

looks like it's going to be a pretty sweat flowering box

very interested to see how this goes. looks good man

Two fan circuits is the most efficient. Always. If the fan can't keep it cool as it is , adding a filter to the circuit will make it worse. The filter reduces CFM by at least 20%, particularly with all those sharp bends in the ducting.
Not sure I understand your light placement. Eliminating any turns in exhaust is the first step to nirvana.The MOST you can expect a 400W to cover effectively is 2.5'x2.5'. You gain a few inches from overlap. If you mount your lights with this in mind, you'll run much cooler. You will need some supplemental lighting in the corners. Lowes now carries true 75W CFL's for $18. Should do the trick for you rather well. Short of rebuilding the cab at 30"x 65", this looks like you best bet.
The more efficient you cool the light, the easier it is to cool the cab air. This means a smaller (cheaper) fan and filter.
Hope this helps,
Fred

Got it finished boys.

4'x4' - 55" tall - 800w HPS - 942 CFM air movement - 77 degrees - Completely light proof

I'm a happy camper. My biggest concern was heat... But my temps are lower now than they were BEFORE I built the box...



I'll get some pix with the plants in there in the morning. They're sleeping now.

If anybody cares... lol, I've got everything finally tuned in and running just great! I posted some pix of the plants and stuff in my Perpetual Journal. It's in my sig, the (4'x4' 800w perpetual grow)

Check it out if ya want