hi people yeah i guess ill try a reverseble one. instead of having the cone inner core becouse i cant predict the result and im affraid that the the thin part having less resistance will suck more and filter less. ive seen those designs used like the don says. but im not shure if it is more or less effective. IMO the filter conected to the end of the ducting is creating a bigger resistance. its like a jam. and it is always better to have less resistance on the way "after" the fan - thats how the fan dealer told me. i guess it also depands on the TYPE of fan ur using - diferent types handle such things differently. anyway it can work both ways i guess. cant wait to build one and compare the results lets do it people! at least we can try))))
ok people i did one this is a really nice model its reverseble and ADJUSTABLE the inner core is constant but the outer one can be made wider i want to smoke now thats why i will post the drawings and instructions later if someone need em its made from a 0.2" steel grid aquarium carbon and sheets of filter material used in your kithen draw the specs: CFM: 300 (180 true) lenght: 20" inner core: 6" outer core: 9" bed width: 1.5" weight: 23 lb and guess what! it works!!!!!!!!!!!!!!!!! it sucks air all the way from the top to the bottom and able to hold a sheet of paper i will post weekly sayng if it still works good or no now i have 2 girls 2 weeks into flowering lets see.....
Replace that aquarium carbon with carbon that was made to filter air or you results will always be poor. I promise you. You can find it on ebay. The guy who told you that aquarium filter was the same as the good carbon they use for air was an asshole. That is the reason my he has a shitty job. "If you want to be a millionaire dont ask a bum how to become one"
i feel u man but there is a reason whyi use that aquarium carbon all local growers use it (for real!!!) people dont get 100% result but it works i dont need to kill all the smell i need it to stay in my apartment) WITHOUT SPREADING TO THE STAIRWAY) i think if i totally fail this project i will order it on e-bay. until then ill see how that works. once again - u r right man tnx
I am about 6 weeks into my first hydro grow. You can check out my grow journal for full specs, etc. My question is, I only have one plant(only female from the 5.) There is only an odor when I open the door of the closet, and it is not overpowering. The only ventilation it receives is when I open the door to check on her(which has been working fine so far) I do have a fan in there for air circulation. My question is, Do you think I should invest in some type of odor neutralizer now? Or wait until I begin my 3rd grow? -C
First off +rep to screw,,, nice work and ty for correcting me on air contact time... Now let me tell ya when ya go to trim what you have grown it will smell about ten fold.... today I harvested about 15 oz's and it reeked my house,,,, so I kicked in a 6inch TD fan on a large can carbon scrubber,,,, it's a life saver for me. Think a head.
tnx man im doing my best and hope its helpful feel free with the feed back everyone especially those who think differently the trouth is a product of argueing (not shure if i spelled correctly)
If I may suggest my thoughts... (Ok, force them...) You want negative pressure through any filter. You never want to "Force" air into a filter. It will fail to function adequately. (As it was mentioned, the issue with more pressure closer to the source of the fan.) You want negative pressure, which sucks equally in all directions, with an unobstructed path to the element. (When you use negative pressure your CFM or CM/h stays more true. Less static resistance.) In the filtered side, you should also have an over-flow flapper. This will allow fresh or room air into the flow, without severely disrupting the static pressure. In the event of filter blockage, the flapper will be 100% open, indicating a clogged filter. The fresh air also helps to reduce any odors that do manage to pass through, via diffusion. The exhaust portion which the filtered air exits, should also have a flapper. This will help ensure that no odor "Leaks" when the fan is off, due to evaporation of odors from the activated carbon element as it cools. You can also setup a recirculation hose, leading back to the grow area, behind the flapper. This will keep inner chamber air pre-filtered, while not exhausting hot air at night. This also helps to reduce the evaporation odors that would normally leak as the carbon cools. In addition, a mini-scrubber that is always on, inside the grow area, is a BIG help. You need circulation, so simply make a mini-scrubber that handles high-flow rates for the chamber. Using 1/10 of the carbon, and change it more frequently. The air should be able to easily pass through the carbon, over and over and over. This pre-scrubbed air will leave less scrubbing for the main exhaust filter. (Same setup, using negative pressure. Filter behind the fan element, sucking air through it.) They sell mini bedroom odor filters rather cheap, around $20.00usd and filter elements that are around $5.00usd. Those would need replacement once every harvest, or three months of flowering. (Some are built cheap, with the fan behind the filter, pushing through, but frequent changes eliminate any real loss. Only a loss of power is not regained, as the fan is over-sized for the application.) Besides time, you must also have surface contact. Positive pressure gives you more potential surface contact, but the high speed volume limits the air that actually touches the surface. EG, pressure is from pushing 1 element with 1000 elements behind it, not touching the carbon. You would need to reduce your exhaust orifice, to obtain adequate pressure, and recirculate air 999 more times, before actually exhausting it. (But we don't need 100% effectiveness, only around 50%, with diffusion from the high air exhaust volume and heat.) With negative pressure, and lower speed, you draw single elements across multiple surfaces, evenly. This method, along with the diffusion and heat, will give you nearly 90%, as in a hepa-system, when it comes to odor molecules. (I researched this when i grew mushrooms... hence the name... "Laughing Jim".) It is better to have a constant 24/7 operation of flow at 1/10 room volume per minute. As opposed to an on/off flow of 10x room volume per minute. If your room is 10 feet by 10 feet and 8 feet tall, assume that plant-space is 8 x 8 x 5 feet. Your volume is 800 cubic feet of space, and 192 cubic feet of odor, (1 x 1 x 3 feet of bud per plant, with 64 pants.)... My suggestion, for a negative flow setup, with an internal circulation scrubber, would be... Exhaust filter, 24/7 @ 50 CFM with a blower-fan. {Squirrel-cage} (Roughly 20 true CFM through the filter) (Roughly 10-30 true CFM from the diffused flapper connection.) {1440 min. x 20 CFM = 28,800 CFD} {28,800 CFD / 800 CF = 36+ Room exchanges per day, external venting.} Internal filter, 24/7 @ 20 CFM with a blower-fan. {Squirrel-cage} (Roughly 15 true CFM through the filter) {1440 min. x 15 CFM = 21,600 CFD} {21,600 CFD / 800 CF = 27+ Room exchanges per day, internal circulation.} For 20 CFM of flow, you want over 2 square feet of filter surface area that is 1/2" to 1" thick. Pre-filtered with nylon cotton, before the carbon, to ensure even distribution of air across the carbon layer. (Hand drilled holes will not work, but nylon-stockings work great as an alternative.) Thicker carbon layers will not extend effectiveness, in high-flow. You would need exponential depth, for faster flow rates, or double surface area. Depth is not area, it is volume. Area is length and width. (Professional filters use an accordion style filter to gain more area in less space. This \/\/\/\/\/\/ setup of 1-foot by 1-foot filters can be reduced to a volume of 1x1x2 feet, and accommodate flow-rates over 400 CFM of unrestricted negative pressure flow, or 100 CFM of restricted positive pressure flow.) ODD NOTES: Activated carbon is activated carbon. Unless the canister or the bag is open, it is all the same. ALL THE SAME... If it is better, it is not "Activated carbon", it has other names. "Activated carbon", is the lowest element on the totem-pole, and the only one in most growers budgets. There are medical and industrial grades, but unless you buy them by the ton... you will never get them. (Industrial is the same thing, only smaller. Medical is the same thing, with all micro-dust removed, and certified.) However, pet-store activated carbon is the worst choice, due to pet-bacteria in the shop and on the shop-keepers hands and poorly ventilated air-systems. Get it from a garden-shop. (Both bags may have holes, or punctures... get one with less, that is not sun-faded.) You can re-activate carbon with UV and heat. (But you release the odor in the process. You need temps over 500F. Though this is not cost-effective, or practical.) You should "Wash" your carbon with hot water, and rinse it with cold, before you attempt to throw it out in your trash. One minute of foul odor, followed by fresh air, may save you from curb-detection. It would normally release odor as it bakes in your trash-can on the curb. It is better to haul it to a distant dumpster, after being bagged with gloves on. (They will get finger-prints off the bag if you don't wear gloves.) A box of baking-soda also helps, if you can not "Drain" the surface odor away. Cat-litter that is used also helps... (Ammonia, Urea, Feces, Clay, Baking-soda mixture helps mask any nosing around of the light odor that would be emitted.) Sorry, no resources, but google mushroom growing, medical carbon scrubbers, etc... (These are all from my old notes, reduced to what I needed at the time.) EDIT: I also wanted to add this tip... Turn-off your internal fans before you enter/open your grow area. Also, turn-on your exhaust, if it is not on. Then crack-open the door for a few seconds to draw air away from the doorway before entering. This will severely reduce lingering odor that would normally escape. You can also link your drying room, to your flowering room. So fresh air enters your drying room, then travels to the flowering room, and then gets filtered and exhausted. (Fresh air being house or outside air going into the drying room first. (All negative pressure, not positive pressure at any point, or you blow unfiltered air into your house through the microscopic leaks in the walls/sockets/tape/doors/joints/etc...) That also acts as a pre-humidifier for the air that goes into the growing chamber. Your dry home-air drys the hanging plants, and the humidified air then moves into the flowering chamber. (Humidified from the moisture released from the drying buds.)
One more thing I forgot to mention... You can adjust your flow-rate, by adding a bypass "U" that connects the suck to the blow portion of the fan/blower. Using a valve in the "U", will allow you to regulate the unrestricted flow through the inlet and outlet, through your filter. Since all AC motors are a fixed RPM, there is little that you can do to regulate fan-speed. (Regulating voltage will destroy the fan. It operates on HZ frequency. Lower voltage will make it overheat since it does not have enough power to complete a turn. Lower voltage translates into higher amp-draw = more watts = fried coils. This is the other reason I use DC fans.) The more resistance you have, the more resistance you create with a higher CFM fan in a positive pressure environment. The compressed air becomes resistance itself. Like hitting a wall of air. (CFM is rated by water movement through the impeller at that RPM. Air is nothing like water. CFM and static pressure are actually a useless measurement for fans that move air. They tell you nothing about how it actually operates. The government has posted warnings about these two false readings, and has even gone after many manufactures that continue to use them. Google it.) I still suggest that you route some of that stinky air back into the chamber, for a second and third round of scrubbing. Google, "Personal air filter", and you will find many $20.00 desktop units that take standard activated carbon filters. Once you have one, you can refill it with your own activated carbon when it is used-up. Great for grow-chamber circulation and pre-filtering. (Just stay away from the ionizer versions, they create ozone that damages plants and reduces O2 and H2O and CO2.)