2 x 600w in a 4x4 area, how much cfm needed to cool it?

Current have just 1 600w up flowering with 8 plants. id love to give them tons of light, but theres no way the fan i have can cool that much heat. I have a 500 cfm blower fan on them right now and the temps stay about 10-15 degrees warmer than my house. the room is being vented out the window just a couple feet away. how big of a fan do you guys think id need to cool that room down?

man to be really honest, you dont really need two 600 in a 4x4. you are getting a good lumen per sq ft ratio. i get 95,000 lumens out of mine so with 16 sq ft you get around 6000 lumens per sq ft. but if you want to put to in there you could go two way. one would be liquid cooled light. and the other vented hoods. like a cooltube then connect the two using 6" ducting, allowing one to have an open side. run a 6" inline fan pulling air from the hoods. this will keep it cooler. also, you could buy a window a/c unit, a hundred bucks or more depending on size, then vent all the a/c into growroom. this will cool it. i have one in my grow cab and can keep it any temp i want by just adjusting the a/c.

I have 2 600's vented like this: Filter>Fan>Hood>Hood>Exhaust. My fan is a 484 CFM 6" vortex. Hoods are easy cool 6's. Temps are around 76 F with lights on in the tent. Ambient temp for the intake of the tent is about 64 F.
In my opinion air cooled hoods will be less of a hassle, less expensive, and suit your purpose. You do have to take into consideration the ambient temperature of the air you will be using to cool your lights. If it's going to always be 85 F where they are then you will be hard pressed to get the heat lower than 88ish no matter how many CFM you are using. That would probably be the only reason I would ever use liquid cooling (I just dont like the idea of water + electricity).

Instead of pulling hot air from the room through the hoods you might want to consider a vent from outside the grow room-->hood-->hood-->fan-->out.
This will keep your room a lot cooler, obviously you need another fan to take out the air from the top of the room where you could easily attach a carbon filter. If you try to pull hot air from a carbon filter and through the 2 hoods and out it seems like it would be less effiecient

500 cfm is more than enough for a 4x4 space

what you might try doing is putting a passive intake from a fresh air source like a window or something. as long as you keep the pressure low in the room it will draw in cool air. that could help keep your temps down. just put the intake low in the room if possible and make sure you put some sort of filter on the intake.