Room setup inquisition

Hi, so I've spent the last week researching here on RIU ways to maximize my grow and I've come down to this design and am hoping for input, especially on the intake exhaust aspects.

Room size 12x8

2 Tents:
Veg tent 4x2 with 2 250w mh, . 6" exhaust fan 240 cfm
Flower tent 8x4x8 with 2 600w hps, 8" exhaust fan 471cfm.

I will be exhausting into the attic. For the intake i was thinking of using a 16" window fan to pump 2400cfm into the room and then using passive intake on the tents via a hole or multiple holes? Or would I be better off trying to suck air from the fresh air vent in the attic? I'm assuming I'd need some blowers for that? Please share your speculations on the intake/exhaust. Very much appreciated.

Cheers

You really don't want to bring your intake from where you are exhausting to. If you are using a window fan, I assume you are getting the air from outside? Since, at least here, it's pretty warm outside I wouldn't get your intake from the warm air as it will raise your temps. Do you have an air conditioner in the room?

Thanks for the reply. If I intake from the attic it will be from the open vent (not sure what you call it theres 2 vents in my attic that take air from the outside.) The room has access to central air, but i cant use a window AC as that is too much power to add onto m bill without red flagging.