It is an in-line duct fan.
Thanks for all the replies. I appreciate it. I would buy a new fan if I could. I will eventually. I am also way too afraid of messing my light up to take it apart.
I am going to hook the 4" up to the duct work for the veg room and the 6" up to the duct work for the flowering room. Does anyone know if this will work, since the duct work for both rooms meets and goes into one line of duct? Maybe this will help. I am also going to get a computer fan to help pull in more cooler air. I just need a solution for a month or so until I can afford a bigger fan.

P.S. - what signs should I look for concerning damage to my plants from the heat? I haven't noticed any yet, but it has only been in the 90's for one day of 18 hours. They still look as healthy as ever.
pot_head_sam Reviewed by pot_head_sam on . First Grow....First Problem....PLEASE HELP!! I just recently turned on my 400w MH (AgroSun). I hit high temps...like 90-94 and I am freaking out. I have a fan that should be bigger than what I need for the size of my room. Let me break it down first. My entire grow room is 3x7x7. I have two seperate rooms. The veg/mother room is 2x3x7 and the flowering room is 3x3x7. I am using CFL's in the veg/mother and the MH in flowering. I haven't started flowering yet...just getting the plants use to MH before flowering around christmas. Rating: 5