Great thread Subcool. Very practical knowledge you're laying down. RIU is lucky to have you. On that note................

Do you ever have issues with all the heat going through that one fan? Also, is there any way to make sure that the air flows evenly through all the hoods. I am wondering if the hoods on the shortest circuit would get most of the air, leaving the hood in the farthest reaches (the veg room in Jills case) to heat up.

Is it a bad idea to run 2k+ in series? I would just hate to have 1 side of a y-splitter get more air than the other; would pushing vs. pulling affect the ability of the splitter to evenly vent both hoods? Hmmmm, that last one seems oddly worded; you know what i mean?