bro you dont need to tear shit up for an hps i grow with 575 watts of mh in a closet and all i do is put one fan blowin on my light faceing the door and another blowing out the closet and leave the door open but put a sheet up covering every thing but the fan and there you have it!no holes in doors or walls.my closet is 2x5x6 and it stays around 70 to 73 deg..i had the same set up in a closet 2x2x6 and it ran 78 in the day and 74 at night

ps.. a 250w hps you wont even need a fan in the doorway just leave your door open with one on your light and you will be fine