My guesstimations absolutely assume that the hood is not cooled- There are just too many variables regarding reflector design to make any kind of meaningful guesstimates.

Could you post up the spreadsheet somewhere? It might save folks some work. Great idea.

I'd probabley just circulate between the two rooms with a couple of 6" muffin fans. You can pick up " starter flanges" intended to run 6" round off of box style manifolds for forced air heating systems- If you mounted one @ the top of each room, w/ the fan blowing thru the partition, thru the flange, and into some 6" flexi that leads down to floorish level in the other space, you'd get a nice flow pattern and built-in light proofing. Should be pretty cheap if you go Rat Shack for the fans. I def wouldn't screw w/ duct solenoids @ that level- too pricey, too complex. Neat, though...

If airflow between partitions is good enough, you can just put the filter wherever's conveniant. You could also use one fan on the exhaust, w/ a y-splitter on the intake and maybe an odorsok in each space.

Don't forget that on-time in veg will be longer than in flower, so there will be an overlap period when both lights are on.

I would def recommend using a ventilating the lights seperately- suck in clean air from outside, blow it over the bulbs, and outside again no filter. Just make sure that all of your joints are airtight, so that you aren't picking up stink from inside. Use the aluminum tape- duct tape will go soft at temperature. Seems more complicated, but it's actually simpler, as this fan is set&forget, and it takes a lot of load off of your main vents. Doesn't have to be much of a fan for a couple of 400s. If'n your feeling sassy, you can stick this fan on a thermostat, which turns it off if temp goes low- allows you to set a temperature floor.

The fans for inter-room exchange and yer hoods should be pretty quiet- the only noise issue is the primary exhaust. You can cut noise by using a larger fan on a speed control- fer instance, you need a 4", but you go up to 6" and cut the fan speed in half- greatly reduces noise. You'll also find that you can tune the sound of the ductwork by varying it's length- imagine a pipe organ.

Sorry I can't be more specific about hood flow interaction, but there are just too many variables, including changes in ductwork length/shape as the hood moves up and down, to make big sweeping statements. If you can be more specific about the hoods involved, I can tell ya what I see...

Hope this helps.

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