My room is 5x10x8 with 2 bare stacked 600's hanging vertically. The exhaust for the whole grow room goes into my central air return with a 10 in scrubber. The out and intake from the air conditioner come from the outside like a window unit so the hot air from the air condition go out the window. My unit is 1100btu's and wont shut off. I guess what I'm asking should the whole room exhaust be on low or high. If its on high won't it just suck the cold air out of the room. How do you guys do it.