Reconstructing grow box. Prototype ( i own 2 of the same display cases).

Ok as of right now my grow box is 2'x2'x3'. Painted flat white with a latex undercoat for mold resistance. I have 3 26w daylight cfl's with coke can reflectors wrapped in mylar and 1 23w soft white.

For my exhaust I am using a xbox 360 fan (stock 2x fan). Apparently this runs at 29cfm per fan. Now my intake lacks. I have a 4" hole in the side of the box. Until I switch to 12/12 this is running my cords out.

With my door off and lights on my temps are 82-84 degrees. When the lights go out I put my door up for darkness (as much as I can). I run my lights on 18/6 from 6am to midnight. At 6am when my lights turn on and I remove the door, my temps are sitting at 90-92!!!

If I were to add another xbox360 fan (another 58-60cfm) and cut 6+ 2" holes in the bottom side of my box, would that be efficient to lower my temps when the door is on? I need to control my temps before I induce flowering.

PIcs make it a whole lot easier to answer. My guess is that you don't have enough of a fan running. 29cfm is pretty weak. If you're going to use a PC style fan I'd be using a minimum of a 120mm fan. One of those is going to much at least twice the air unless you get something that only running at 1000 rpm. I run twice the passive as the exhaust so if I have 1x4" exhaust I have 2x4" intake. In your case I'd probably just put a bigger fan on the exhaust and then use the xbox fan on one of your intake holes.

first of all that is a confined space...not sure what size bulb u are using but i would sya anything above 400watt hps and u should expect to have non stop heat problems until you increase the size of your box

one thing you can try is reversing your light regiment so that the lights come on at 5pm when the earth starts to cool and off at 11am when it starts to really heat up again, that should eliminate external heat concerns and give you a little slack

Edit: also it would be really worth you while to splurge on a 225cfm exhaust fan... use of small dc fans is inefficient for the amount of space you want to cool. Remember you dont cool things off by making them cold, you cool them off by taking away the heat...so an effective exhaust will be sucking all the hot air out of the box before it has a chance to react with surfaces and heat them up

I am using CFL bulbs in this grow. Everything is fine (for me anyways) until it is lights out with the door on thats when things heat up. Unfortunately I don't see changing the light regiment helping. From midnight-6m it should have time to cool but doesn't do that.

I'd put in one more intake and another fan to blow out. Intake at the bottom and blow out at the top, heat rises so you'll be removing the hottest air faster and your plants will get all that lovely moving carbon dioxide. This is just me, though, and I'm a newbie. Just seems like one intake isn't going to be able to distribute enough air to do much good. It's like having a crack under a window letting air in or opening the window - big difference in air flow.