I have a 400 watt hps the tent is 3by2 and 5 feet tall. I have a 4 inch inline fan I think its 172 cfm to pull the air from the tent now my question is since im renting my house I dont to go putting holes in the walls so im wondering if there are any other ways I can get fresh air for inside the tent I have a open hood and am on a budget for things to cool the room