I have a DragonStrand Large Atrium (45"w x 22.5"d x 44"h). It's the clearsided version, so overspray is less of an issue. I started out with 4 in front, 1 in each corner and a double-nozzle in the middle. However after a month, I felt the back did not get enough so I added the same in the back. (Probably just a double-nozzle in the back-middle would have been OK.) If all the sides were screened, I'd probably have too much overspray.