Kind of agree with everyone on the hood subject. Grown both ways and there are advantages to both. I'm going back to bare bulb though.

I grow in a gorilla 9x9x8 at the moment, with bare lamps I'm alright since I have the 18k split. After this crop I want to expand to the 6k. I figure I could recycle the heat in the basement and use it to heat the house a bit.

I understand you lose roughly 10% on the lighting output. That was my concern. Although with all the btu from humidifier, co2, etc... I didn't want to make the new split system work too hard.

*Is bigger always better? ----------------> Depends on the set up….some rooms don't have the head space for parabolic hoods or free hanging bulbs.

*How can a hood with 6" or 8" holes cut out of two sides get maximum lighting down to your plants? -----> I can assure you they do. I have NO problems achieving 2++ per Every harvest with my current set up.

*With all the $$$ you're spending on electricity why would you use a hood that'll block 10%+ of one of the most important aspects of indoor gardening with a glass shield? --------> As Sixstring pointed out, the hoods keep the room cool enough so that the a/c doesn't have to be on hardly at all.

*If you still have to cool your room after setting up a/c hoods, why use them?????????? ----->> because I don't have to run my a/c hardly at all or for longer periods of time, which saves $$$ in the long run.

*Doesn't ducting have to be properly installed to effectively remove the heat and prevent excessive loss of cfm's? -----> Absolutely…not difficult task to do.

*Do the pros use a/c hoods? Not the peeps who think they're pros I'm talking actual gardening professionals---->> Some yes, some no….again, it all has to do with the set up.

I think I got my answer here, thanks a lot fellas. Enjoy the 4:20 tomorrow!!

I ran 9 light rooms air cooled, in a basement and each room only had a 2 ton mini split, and it kicked ass. In that situation they were critical. It was in a cool climate and the house was on 5 acres, so smell/noise was no concern.

Now I run bare bulbs, or AWW for the sheer fact that air cooled hoods leak smell and I can't risk that, nor do I want to exhaust a bunch of lights out of my building.

Different strokes for different folks

You make a really good point billyboat about different strokes for different folks. Additionally, thats a good thing to take into considering, the smell leaking through air cooled reflectors. I never thought of that although I run a 8in. scrubber inside the room and another one on intervals outside, just in the general area.

I use the following:
1. scrubber for drying room, only on when material is in there
2. scrubber for grow area, runs 24 hours when plants are in there
3. scrubber for common area, on timed intervals 15 mins on every hour

Although the thread isnt about clean air, the point you made was important. If I were to constantly circulate air within the basement running through lights, the air in the basement would be scrubbed 24 hours.