when i grew in my closet i took my door off so i didnt have 2 cut holes in it, i made a thick door out of 3 u-haul boxes, i opened them up and stacked 2 gether so the door was thick, in a closet that size with a 1000 its going 2 get hot and humid, your going 2 need 2 get that hot air out and fresh air in, i would use a 8 inch fan 2 pump the hot air out, mount the fan inside the closet on the roof, fans push better than they pull, cut a hole in the cardboard door and run flexible aluminum ducting 2 where ever u want the hot air 2 go and seal the ducting 2 the door with expensive duct tape dont use the cheap kind the heat makes it come off, i was up stairs so i pumped mine out a window, the air coming out is going 2 b hot it will heat up a room, cut a 10 inch hole at the bottom for your fresh air intake, if you have central ac you can run your air in from the room just make sure your air is on when you lights are on, if you dont have ac run your lights at night and use 10 inch ducting 2 bring in cool air from your window, the temp and humity is very important when growing indoors put a thermastate in the closet 2 make sure its not 2 hot or humid, your going 2 want your temp between 75-83 in veg and humity in veg around 80, in flower if you can keep the temp at around 75 and keep the humity no higher than 50, if you humity gets higher in flower youll get power mildus and mildu, its going 2 be all little work tying 2 get your temps and humity right in that closet cuz you can fit a ac in there, good luck