Hi guys - I am in the final design stage for my grow room and was wondering what size of fans I will need for my ventilation. The room will be 4.5ftx2ftx6ft - I was thinkin gof using 2x120mm PC fans- 1 to blow cool air over my light/ reflector and 1 to extract the hot air from the room. Sound about right, or am I gonna need to go bigger?