what would be better for stopping heat 4 x 600 HPS 2 x 1000 HPS only have 4 pots hydro in a shed 1.2 x 3 x 1.8
An area 1.2 x 3m would suit 2 x 600Watt lights.
If you wanted to put 3 600’s in there do it when the temperatures are under control.
Use lots of fans, and exchange the air for fresh air
Don’t run it around and around the room.