Ventilation question

Ok so i am planning on started a small closet operation in the house i am about to move into. So ive been researching the hell out of everything and i have pretty much a good idea of what how im gonna set everything up but i dont know how im going to ventilate the area. I plan on using a HPS/MH system but i cant really cut a hole anywhere to ventilate since im renting. Also since my house will prob be used for parties i will have to keep the door closed for extended periods of time. How can i deal with heat/lack of CO2 in this situation. I know i can us some sort of CO2 generator but what about the heat? Any ideas? Im open to anything that i can do that can be either fixed easily in the end or something like that. anything will help...

you could section that part of your grow area off from the rest of the room so most of the heat will be in there. and you can vent right into the room cause it should be a few degrees cooler, or you could put a small air conditioner in the room if really need be.

so the closet is about 4x8 ft and i was planning on sectioning off about half of that- if i ventilate the sectioned area into the the non-growing area- would that be ok? do i need more than that? also if i do this would i still need an additional CO2 source?

my closet is about that as well and i have sliding doors so all i do is leave them open on each side a few inches and have one box fan pulling air in and the other pusing air out the other end and it keeps my area at 77 and im using a 400w hps. co2 is almost always benificial when growing indoors i wish i would have used some on this grow.