Ventilation required!!!!!!

I have a 5x2x7 closet that I will be using as my grow room. I own a 400 mh&hps set up already. It came with a batwing reflector. I have a big duct exhaust fan just can't remember all the details since it has been 4 years since my last grow.

I was thinking of getting a cool tube reflector to cool the light off. What type of ventilation setup would give me good grow temps in this closet area?