I just cant understand some peoples mentality, wtf are you doing trying to put a 400w HPS in a pc case, thats just a fire waiting to happen, make a small box and go 250w hps, thats a little more tangable, a 400w will take up 50% of the room, if you think your going to increase your final yield by increasing the lumens and light intensity in such a confined space, enjoy watching your babies burn like a albino at the beach, im not dissing you out, im offering some advice that will benefit you in the long run, you should re visit your plan and make some major adjustments to be successful. good luck.