Grow Box Info.

This is my first time building a grow box or for that matter my first time growing weed. The box is in the basement and it's 90% done, 4' wide, 2.5' deep, and 5' tall, then a pitched roof. It will have a 400 watt HPS with a MH conversion bulb, i plan to have 2 small fans inside with a 6" inline duct fan for the intake, and a 6" inline duck fan in the roof, vented to the chimney. Will this be good enough for venting and cooling. I'm learning a lot from reading these messages.
Thanks

ohh shit....i am in almost the same situation .......im a first time grower and im building a box almost the same size .

hows that working out for u????