OK MY ROOMS ARE BUILT ONE ROOM IS 9.5 FEET BY 4 FEET 8 FEET HIGH, WITH 2 400 WATT HPS INTENDED FOR FLOWERING THE OTHER ROOM IS 6.5 FEET BY 4 FEET WIDE ALSO 8 FEET TALL IN THERE I HAVE A 6.5 FOOT LIGHT MOVER WITH A 400 WATT METAL HALIDE INTENDED FOR VEG. O.K. EXHAUST IN THE FLOWER ROOM I HAVE 2 HOME DEPOT 50 CFM EXHAUST FANS BLOWIN FRESH IN THAT AND ARE MOUNTED AND A 110 CFM EXHAUST BLOWIN AIR OUT. NOTHING IN VEG ROOM YET, BUT I BOUGHT A EXHAUST THATS A GREENHECK SP-127 AND ANOTHER EXHAUST THAT PUSHES ABOUT 250 CFM WHAT SHOULD I DO WITH THESE 2. CAN I HAVE THEM BLOWIN OUT, IN, ONE IN, ONE OUT, IM THINKIN USE BOTH AS EXHAUST. THE BUILDING ITSELF IS 16 FEET BY 4 FEET OUTSIDE ALONE. THE DOOR TO THE BUILDING FIRST GOES TO THE VEG. ROOM THEN A DOOR IN THERE GOES TO THE FLOWER ROOM.

well you did the right thing for using hps for flowering and mh for veg. as for your exhaust problem. veging process doesnt need as much exhaust as blooming does. i think you should switch the 250 cfm with the 110 cfm in your bloom room. this way the humidity lowers and prevents bud mold and other mold. You really dont have to worry about much for vegging. just put one exhaust fan for vegging and no input fan. (use the 110 cfm for veg exhaust.)