another vent question

hey my closet is 5/3/6 and my ceiling are those removable tiles, if i use a 400W hps light would it be a bad idea to just remove one of the tiles a bit to let the hot are out? or would this heat cause fires or something else lol. i still live with my parents and ofcourse they have no clue i dont want to vent it out the door cuz they would see that. Also would i need to get a fan to pump out that air or would the heat just escape thanks

This is a bad idea. First it is not acceptable to grow in a place you don't own or pay for yourself, your parents could lose their house. Second, putting all of that hot humid air in the attic will cause mold to grow in the attic until winter, which will kill the mold, make ice out of the hot humid air and eventually rain into the house. How old are you?? VV