So im setting up a new grow room, the room measures 7.5'x8.5'x8=510 cubic feet. I have a 1000w MH/HPS and plan to grow 9 plants all same strain still undecided as to which strain. I plan to use 5 gallon buckets from home depot and fox farms full line, soil, ferts, solubles, etc. I used 24 hours of light on my last hydro grow so i figured id stick with that for this grow. Im not too sure what to do about ventilation. Ive read online that i need to exchange the air once every 3 minutes so 510/3=170, 170 cfm is required. I figured id aim for 200cfm and run the fan 24/7 to properly vent my room. does this sound about right? I also plan to run a portable ac/dehumidifier unit in the room to make sure temps and rh stay where it should. a small space heater might also be implemented into my room just to make sure temps dont drop too much while the light is off. Please let me know your thoughts and if you have any sugestions they will be greatly appreciated.
200 cfm is enough. However I would go as large as you can with that 1000 watt. They get mighty hot. If you direct vent your light on it's own ventilation loop with like a 200 cfm inline fan it keeps the light nice and cool. Then 200 cfm exhaust would be plenty. This is how I run mine and it stays really cool. I just use one of those cheap 6 in. inline fans you find at Home Depot. They are like $25. Leaves plenty of $ for another larger exhaust fan.
I found a 200cfm ceiling mounted bathroom fan at home depot, I wonder how well something like this would work? It even has a 4' flange so I can duct the exhaust from the room into a carbon filter if I end up needing one. Also I have roughly a 18''x18'' hole at the in one of the bottom of one of the walls, I was thinking I would just put a big vent grate over it with some activated carbon mat on the outside of the grate, this would act as my passive intake. Any thoughts on that?
I know from experience that the bathroom fans don't work well for growing. At least not for the money you will spend on a good one. The passive intake idea should work well though.