first time grower question about lighting

i have a 400 watt HPS light and the growing area is around 3ft by 3ft in an exterior shed off of my apt. balcony. My question is, is it necessary with a 400 watt light to get a vent in there too, or could i just put the light and a fan in there only?

excuse my poor grammar, im sooooooo high.

you should exhaust your grow area because your plants need fresh, cool air (so don't forget an intake hole also). keeping things cooler is a fringe benefit.

yeah the light needs exhaust and the room needs intake