very helpful reply seriously not being sarcastic incase ya think that +rep for ya and ill stick with pc fans at the mo and if it gets maaaad hot ima get a propper thang
If anyone can think of questions that should be included whether they have the answer go ahead and post it and hopefully it will get answered (common ones I can add to the FAQ 1st post and have it unanswered) well worded and thought out questions deserve rep and should get them by all who read them.
I have a an 8 inch (400cfm) and a 10 inch (500 cfm) axial flow fans cooling a room that is 10 feet x 4feet x 5 foot high. The room is airtight and I am using the 8 inch as an intake fan to create positive pressure and the 10 inch to draw the air from 3x 5 inch cool tubes from the lights (1x 600 hps and 2x 400's and about 5 feet of 5" ducting each ) through to a 10 inch carbon scrubber- I am yet to run this system as I have just finished construction of the room but I am now worried I should have purchased /used squirrel cage fans (or at least one for the exhaust through the carbon scrubber).. So I guess my question is will my 10 inch axial fan be able to suck the air through the 3x 5 inch ducts and cool tubes and push it through the carbon scrubber with any success? I figured that because i have positive pressure created by the 8" intake fan that the 10" exhaust fan would be able to cope but after doing some reading I am not so sure that these type of fans can cope with having to create pressure into a a carbon scrubber? any advice is appreciated - BTW its winter here so I am hoping these will get me through my first grow with lower winter temps and if I need to upgrade for summer so be it)...
Personally I would make them both exhausts and and run one through hoods sealed intake from another room so you don't have to scrub it. But you should be okay. An 8" and 10" fan regardless of being axial should move some air and should be able to fight against a little pressure. Lets look at some numbers... 10x4x5=200 ft^3 You need to replace the air every 5 min. So you would need bare minimum of 40 CFM (actual) air exchange (200ft^3 / 5min). Lets say the smallest fan runs at half capacity from filter alone. now its down to 200CFM and lets say that gets cut in half from the ducting so 100 CFM. You should still be in range of air exchange needed for the girls fresh CO2 needs. I would suggest doing a dry test run and seeing how the temps look. But as far as needed fresh air you should be covered.
This is what I was initially planning to do but as this is a stealth room I (by location and design) do not have this option unfortunately- hence me using the fan I had intended for the cool tubes to be sealed lights only cooling to be used as an intake only fan and hoping it would help the 10" exhaust fan-- so my current ventilatoin diagram is : >>>air coming in >>> sucked in by 8" intake fan >>> swirls around room >>> through 3x 4-5 foot 5" ducts to 10" fan >>> carbon scurbber >> outside
Hey all and OP...I currently have a grow going on in the closet of my room. I have a small 1BR apartment (no more than 550 sq ft total), and early in flowering it started to reek, badly. So I modified my air purifier into a carbon filter. Since I already had this one and wanted to prevent buying ducting, blower fan, etc, I decided to give modifying a little a shot($35): Holmes HEPA-type Desktop Air Purifier - HAP2400B-U and stood it upright, then took drywall mesh tape, measured the surface area of the intake grate, put a few layers of the tape together and lay it down on the grate. Then after washing the activated carbon, spread about an inch or so layer on top of the mesh. Put another double sided mesh screen on top, secure it, and then put the cover back on. (No HEPA or anything other filter). It worked, the smell was gone, and then gradually seemed to come back around 2-3 weeks later. I chalked it up to the carbon needing to be replaced, and that helped a little, but my apartment was still smelling pretty bad. This was about a week ago. Deciding that the risk of the smell leaking into other apartments much longer was a risk I couldn't take, I went to wal mart tonight. This time I bought this air purifier for 25$: Holmes HAP223 Odor Grabber with HEPA-type Filter HAP223-UC2 - Air Purifiers Odor Grabber and did the same thing, standing it upright and using the mesh, activated carbon. I put this in the closet (before I had the other one in the room outside the closet), and along with the other one...this seems to be moving enough air through carbon to solve the issue. Not the cheapest option, but it was 'quick and easy' in a sense, especially if you already have an air purifier of this type. Just wanted to see what OP and all you fine blades thought? I can post pics if anyone is interested in seeing how I did it (if you are in a pinch and have limited resources--or wal mart is the only place open at 2am and your apartment stinks from your plant or two, haha) Also wondering if anyone knows if it would be dangerous to have activated carbon at the top with the 'ionizer' on? I don't want the carbon dust to spark or anything? Anyone know if there is any reason I should be concerned about that? (They ionizer function on both are turned off at the moment)
Well, what I did seems to have gotten rid of the smell for the most part. I can still smell the girls if I put my nose up to a bud, but when the closet is closed, room no longer pungently reeks (more contained smell I suppose is what I'm trying to say). If it comes back with a vengeance, I'll look into another filter to throw in there and maybe an ONA as well just to be safe.
I'm about to go get an inline fan from my local hydro store. I did the calculation you have up there, but it doesn't seem to be right! 4'x4'x6.5' / 5 = 104 feet^3 / 5 = 20.8 feet^3/min 20.8 CFM. That just doesn't seem right. Shed a little light here, bohbo?
That is correct for bare min airflow. Rule of thumb is replace the air once every 5 minutes. I like every minute. So by every minute you need 105 CFM AIRFLOW not fan. IE duct wrinkles, bend, leaks, all reduce CFM. you need to maintain 20 CFM for plants to not die. But for cooling it needs to be higher. I would go by replace room in air every 30-60 seconds to account for any reduction of airflow so either 105 CFM or 200+. Personally I rather have too much of a fan than too little.
Thank you! I have my eye on a 180 CFM at the hydro store. I was reckoning that it would be enough. I may fork over a little extra to overhaul my air and get a larger one. Thanks for the light that you've shed, bohbo!
I am going to be using a 10x9x8 room with a window that will be covered with a hole for incoming air with a fan attached (centrifugal 6inch 450cfm) and another for outgoing air into the cieling(same fan.) I had ordered both thinking I needed both as thats what I have heard. I will be using 2 1000 watts with a total of 40 plants in a 10x5 resivour on the ground. Should I still use the fan for incoming air, and if so what kind of schedule should the fan be on; when the lights are on only. lights off only, or a mix of the two? I also have an atmospheric control unit that allows for a dehumidifier (have not purchased yet, waiting to see if necessary especially being in California where humidity is not to big of an issue) temperature control, co2 regulation, and night cycle functions should that be used to regulate either the incoming or outgoing air fans? My goal is to produce a high grade medical cannabis for personal use as well as for the use of my collective, with high yields and high potency. Decided on the California exclusive strain Blue Dreams just to give you an idea of the strain that will be in the garden. Thanks!
Blue Dream from Oaksterdam? Good choice! 1) You don't need incoming fan especially if you are using CO2 its just going to hinder things. 2) Both fans are good, here is what I would do. Set 1 fan up on hoods and pull air from that room to run with lights on Set other fan up to vent the room only and leave that on 24/7. See how that goes before you spend money on Co2 and Enviro controls If you decide to go Co2 you can very easily seal things up and use 1 or 2 fans for hoods and 1 for venting room on a schedule like on 5 every hour or something like that. And then attach hood to an air source outside room so its not sucking your CO2 out. Let me know if that makes sense.
Yes the dream! Its some good stuff. I'm sorry I was not clear lol, I have the option for co2 control and it will disable to exhaust when it is supplementing, but no system yet maybe after a harvest or two. Does that change anything? I would imagine it might. Should the incoming air be directed using ventilation tubing to the lower part of the room for good air circulation even with out the fan. I will also have an oscillating fan with a cool "W" pattern option to give that natural wind feel to the plants. Thanks for the quick reply btw. +rep
Well you can future plan for CO2. But without CO2 injection you need to vent the room. I do not suggest CO2 for at least a couple grows. That being said I would use 1 fan to vent both hoods. On when lights are on (venting room when its hotter) IE <fan> <ducting> <hood1> <ducting> <hood2> <open flange> have that on the timer with the lights. Have the other fan on 24/7 just venting room. This requires 2 carbon filters if you want to remove the sweet odor. Alternately you could pull air from another room for the hoods so <hood2> <ducting> <intake from another room> Then you would only need a filter on the 6" venting the rooms air. Either way you could adjust for CO2 later.
I will do that then, will the ozone generator cover the smell? For the intake hole shouuld i use ducting to direct the flow of that air to the bottom of the room?