Ventilation Question

[Prodaytrader]

I have a 6' square area that is about 6 feet tall for my grow room. I have a air cooled 600 watt hps/mh light. The grow room is located in my garage which has no ceiling and thus is exposed to the attic as well. I will be sealing my grow room off with a set of doors on the front much like a closet or something. The salesman at the local hydro store told me that the best solution is to run air ducting and a fan to the light hood and close it off from the circulation of the grow room but I was hoping to draw air in from one side of the reflector from the grow room. Then put a intake port at the bottom of my room. The idea here is that the fan connected to the duct would suck air through my grow room and into the attic and then finally into a scrubber. The salesman almost laughed at me. He thinks I should put a dedicated duct and fan going into and out of the attic for the light source. Then put a fan and a carbon scrubber in the room and not connect it to anything. The scrubber would just recirculate the air in the room and scrub it. If I do this I would still need an intake and exhaust port for the plants to get fresh air but then I start to lose my ability to control temperature. Since the grow room is in the garage it wont have direct temp control but there are ways around that such as using heat from the light source. I'm pretty confused on how to run the proper ducting for the light as well as the room as well as scrub the air! If I absolutely had too, I could figure a way to suck fresh air from the house into the grow room. Any ideas?

[JackdaWack]

I think u had the right idea, there's no wrong way to do this just what works for you. You need recirculating air no matter(unless u use co2) what so u should have laughed at him. You may not need to vent the hood if u need heat. so u can take the ducting off on cold cold nights. U might as well set up your ventilation in one strait shot. You would use separate ducting for the hood if u were really fighting high temps + venting for the room w/ a scrubber.

I would do this, connect the venting from the hood to a inline, then to a scrubber in the attic. Is the attic sealed off from the garage? As for intake its up to u. where ever will keep the room cool but not to cold.

[LOC NAR on probation]

What your talking about with your light is what we do. Intake is at the bottom of the room. Exhaust through the light and out the top of room. In cold wheather the exhaust is taken off the light to leave some heat. Room is also A/Ced so we need the heat sometimes. We don't use a scrubber we love the smell all down the block. LOL.

[Prodaytrader]

LOL...to the smell/scrubber comment. Ok so then I'm not a total retard for wanting to vent my room this way. I guess I'm just surprised at the salesman's reaction, but then again, he tried to sell me 500 dollars worth of stuff that I got for half that or less on ebay. Like you I will probably need the heat to some degree through the winter. I will probably be fidgeting with the heat reflector and my ventilation quite a bit. I need a good remote thermometer that I can attach to the inside of the room and take measurements outside.

[bongtokeweed]

i would bring the air duct in through the ceiling then t-y it off so it goes through the light system and the y gos through a carbon filter which would also supply cold air for the room. then on the exhaust of the light add another t-y at the top of the room to suck air out of the room and out of the light. bring the exhaust out of the top of the room and put another carbon filter to eliminate odor and a fan attached to create negative pressure to help suck the air out of your grow room. this way the room will be supplied with fresh circulating air and you can control the temperature by putting a thermostat in the room that controls the air system. and if your using your homes air system you may think about installing a zoning system to take use of one a/c system for your home and grow room. if you have any questions ill answer to the best of my ability :)

[dejayou30]

I think the rule is to exhaust up high and make your intake come in low. That way the high temps rise and get sucked out, and the fresh cool air comes in low. I think it would be fine to leave one end of the hood open to suck grow room air in. The hot air you are trying to eliminate won't have anywhere to go anyways. For an intake I just used a 20"x20" vent low on the wall and a box fan pulling air in through a filter. Also be careful venting hot moist growroom air into an attic because of mold risk to your entire home. I never really had to deal with smell when I was growing DP's Master Kush.