yes you will need some type of ventelation, depending on your light size and fixture i would run an air cooled fixture with a fan venting the hot air from the light. have you thought about a carbon filter? you should also at least run some type of fan to keep the air circulating around your plants such as a 12 in oscilating fan.
I just set up a sun hut XL this way and it turned out very nice. good luck bro