Running 2x150 hqi and 4x54w T5 Marineland fixture over a 60 gallon frag 48x24x12. Just measured bottom of fixture is 2 1/2" above the rim of the tank. There's a 40g frag below 36x24x12 with a 70w halide and some diy led strips. The T5 run 10hrs and the 150w halides run 4hrs along with the T5. Think the 70w runs for 6 hours and LED 9-10.
Both tanks are on an open stand with power heads moving the water across the surfaces. System evaporates about 2 1/2 gallons a day.
With the A/C on and ceiling fan in the room the temp rises two degrees. When it's cold (for Florida) I leave the window cracked. I came home tonight and my son said he loves the fish room, it's warm in here.
I would go for it closer, could always add a fan to blow across the top of the tank and another across the sump or vice versa if either works by itself. A temp controller could be helpful as well to turn fans on and off