Thanks for confirming that some of the things I've been planning (and didn't mention) are in agreement with your suggestions, and for the following ideas:

1. I'll look into the washable carbon filter, Odor-Sok.

2. For the exhaust/odor-control, I'll use a speed-control to cut the RPMs of a larger fan, thus reducing the noise (as compared to a smaller fan blowing full-tilt!).

3. It hadn't occurred to me that a muffin fan running continuously can move a lot of air between the two closets. And when you consider that a small muffin fan cools a PC which uses 200-250W, a muffin fan would probably cool the enclosed lamp well enough.

What CFM would cool a 400W enclosed HID lamp if the ducting were simply straight through (with just 4 feet or so of ducting)? I can use your exhaust formula to take into account the true loading: 3 to 4 feet of flexible ducting, either:
a.) entering and exiting the TOP of the closets (to avoid two 90-deg turns had I cut holes in the closet SIDES) snaking down, entering/exiting the lamp, then up/out, totally to 6 to 8 feet while making only two 90 degree turns, or
b.) entering and exiting the closet sides, with two additional 90-deg turns, as compared to situation a.) above.

I'm not committed to a particular type of hood yet (I'm still planning my first grow!). I'm thinking about a home-made glass bake tube, or perhaps will spring for a store-bought enclosed hood with a large reflecting surface.

Oh, and I'm working on finding a safe place to upload the spreadsheet with all the exhaust-loading formulas entered. Any suggestions to protect my anonymity and security, while still sharing the file?
search1st Reviewed by search1st on . Noob's guide to growroom set-up : a work in progress Ms Stinky has shamed me. :( Back when she first hung the ??complete noobs guide to growing?, we talked about doing a ?? noob's guide to grow-room set-up?. I never got around to it- then I saw her ?? garden type examples thread?, and it guilted me into getting my ass in gear. So here we have ( at ) it- the ?? Komplete Noob's guide to setting up your first growroom.? I'm gonna start with some meta stuff- questions to ask yourself before you even start. After that, ( I think) Rating: 5