Thanks bob, ballpark is fine, as a friend of my dads says "building a room not a piano..". I have a 6500 btu and i think i have to at least try it first with the double window fan set-up and cross my fingers that it provides enough ventillation. I feel a little better hearing about your set-up but am still a little guarded as the majority warn against. I appreciate your time and input everyone. temps are ok , weather is great here now, but anyday high 90's to 100's+ til sept/oct.