Tutorial Ventilation 101

[h^2 O]

this is an awesome thread!!!
I'm having issues right now...i have no ventilation...just whatever cracks are in the cabs walls and the seams and a fan blowing on the plants inside. I BELIEVE I am starting to see air problems on the plants - tiny bit of curling, especially on the seedlings, and a tiny bit of yellow hue on a few, and one plant that just keeps growing new sets of leaves all clumped together with hardly any spacing between the nodes.

 

[Grønn]

this is an awesome thread!!!
I'm having issues right now...i have no ventilation...just whatever cracks are in the cabs walls and the seams and a fan blowing on the plants inside. I BELIEVE I am starting to see air problems on the plants - tiny bit of curling, especially on the seedlings, and a tiny bit of yellow hue on a few, and one plant that just keeps growing new sets of leaves all clumped together with hardly any spacing between the nodes.

Sounds like you might have some grey mold going on: Usually when i've seen that clumping together you're describing it's due to a fungal infection.

Your plants need fresh air. Get an extractor. Either your growing pot or you've just made a torture chamber for plants. You decide.

 

[h^2 O]

I ripped out a good 5" hole and placed the fan against that hoping it will suck in outside air. ?

 

[HaroldsHomeboy]

great thread

 

[Grønn]

I ripped out a good 5" hole and placed the fan against that hoping it will suck in outside air. ?

Better than nothing, but best bet would be to provide passive intake holes and an active extraction fan.

Sounds like you're a micro grower so my top suggestion would be to use computer fans.

Old PCs are a dime a dozen so you should be able to get a hold of a computer power supply and a couple of computer fans for nothing.

Plenty of fantastic micro grow cab threads here on icmag. GL

 

[majortom9]

This is like NASA shit man :l

 

[driska]

hello everybody! i am new in the forum. I want ask about ventilaton. I will buy box XXL+ 280x140x200 i will put 2x600w. i want connect carbon filter and ventilation tru the cooltube. carbon filter 1000M/H and ventilators 780 m3/h or 980m3/h. and two input ventilators 190 m3/h. Is this ok setup or you suggesting something different. sorry about my englih. Thanx

 

[Bake_McBride]

Anybody have any experience with these?

http://www.harborfreight.com/8-inch-portable-ventilator-97762.html

Low speed is 1400 CFM and High Speed is 1575 CFM. For $75? Assuming this thing can handle running 12 hrs/day, how many 1K lights would this cool? Doesn't look that hard to modify for our applications. Think I may give it a try.

 

[supermarkio]

I've got a 2x4 tent with a 600w ballast and 6" ac reflector and am struggling to figure out what I'm doing for ventilation. Originally I was going to buy a 6" vortex and pull everything through the light, as is shown at the beginning of this thread. After reading about the 2 stage ventilation I am convinced that this is the way to go. When I get down to working on the details there are a few things that still confuse me. Would you have the larger fan cooling the light, or ventilating the space? What would be ideal ventilation for a 2x4 tent with an ac 600w. My buddies got 2 4" blowers and a cheap 6" duct fan that he may part with but if I have to I'll go get 2 new fans and a scrubber. This seems to be a pretty high tech thread so sorry to bother with my newb questions but it seemed like the best place to ask, not wanting to start a new thread. Thanks

 

[Grønn]

I've got a 2x4 tent with a 600w ballast and 6" ac reflector and am struggling to figure out what I'm doing for ventilation. Originally I was going to buy a 6" vortex and pull everything through the light, as is shown at the beginning of this thread. After reading about the 2 stage ventilation I am convinced that this is the way to go. When I get down to working on the details there are a few things that still confuse me. Would you have the larger fan cooling the light, or ventilating the space? What would be ideal ventilation for a 2x4 tent with an ac 600w. My buddies got 2 4" blowers and a cheap 6" duct fan that he may part with but if I have to I'll go get 2 new fans and a scrubber. This seems to be a pretty high tech thread so sorry to bother with my newb questions but it seemed like the best place to ask, not wanting to start a new thread. Thanks

Your setup seems good, you should have no problem cooling a 600w with two 6" fans. I would rather get new fans and scrubber than old stuff, but I guess it depends on how your cash situation is. You could easily cool your set-up with one 6" and two 4" as well, but you would have to get two 4" scrubbers.

On the question of where to use the largest fan - it depends on your ducting. I would normally use the most powerful fan on the carbon filter. Smell control is very important, but if the ducting for one of the loops is longer you should consider using the most powerful fan on the longest run of ducting.

I would also suggest to get some kind of fan controller with a termostat. Keeps a steady environment and reduces noise. Very useful.

gl on your grow

 

[supermarkio]

thanks for the reply, I'd like to save where i can but if equipment is needed I can get it. I've been thinking about going with a low odor strain (Bogglegum maybe?) and skimping on the filter, hoping that that would help simplify the ventilation. Would a single 6" inline fan, vortex or something of the sort and one 4" blower get the job done? without a filter would the bigger fan want to be cooling the light with the blower taking care of the grow space? I've been planning on buying a fan controller, I liked the sound of the CAP with the thermostat but it is $60 compared to $20 for the simple controller. I've been debating this myself and hopefully someone has a more experienced opinion than my own. Sorry for the many questions, that probably seem scatter brained, I feel very flustered though, I should be set up by now and I fear i will never finish! Any ideas and help will be hugely appreciated.

 

[conehead]

Thanks a million!

Thanks a million!

Very informative thread. Much appreciated by this little black duck.

 

[Grønn]

thanks for the reply, I'd like to save where i can but if equipment is needed I can get it. I've been thinking about going with a low odor strain (Bogglegum maybe?) and skimping on the filter, hoping that that would help simplify the ventilation. Would a single 6" inline fan, vortex or something of the sort and one 4" blower get the job done? without a filter would the bigger fan want to be cooling the light with the blower taking care of the grow space? I've been planning on buying a fan controller, I liked the sound of the CAP with the thermostat but it is $60 compared to $20 for the simple controller. I've been debating this myself and hopefully someone has a more experienced opinion than my own. Sorry for the many questions, that probably seem scatter brained, I feel very flustered though, I should be set up by now and I fear i will never finish! Any ideas and help will be hugely appreciated.

Don't skimp on odor control. Don't skimp on odor control. Don't skimp on odor control.

Even the so called low odor strains are more than able to stink up your house. Unless you live in total isolation and don't mind your house smelling pot you should allways have a carbon filter.

You should prolly be able to cool your set-up with one good quality 6" inline fan and an air-cooled hood. Depending on your ambient temps and if you need to do a long duct run to vent outside.

carbon filter|fan|air-cooled hood -----> exhaust outside.

Connect your fan directly between your hood and carbon filter without ducting if able. Every ducting run increases risk of smell leaks and reduces efficiency.

And the thermostat controlled fan controller is a big bonus. The noise reduction alone is worth it.

Good luck on the grow, and keep on keeping on.

 

[LIFER25]

I need some opinion on how to set up my 4" fan/carbon filter combo. My grow tent is 3ft tall x 2.5ft wide x 1.5ft deep so i dont have much room to work with. Below is a picture of how i have it set up right now. Would it be possible to fit the fan and filter inside the tent on the other side of the light and duct it through the side duct? Or can i place the fan and carbon filter outside of the tent and would it still be effective this way? Also can i connect the fan to the filter like how its on the picture? Any help would be appreciate it.

 

[TheGanz]

I need help finding out whats the best option for my setup. Im in a 4x8x6.5 tent. Am I going over board by having a 600 cfm fan cooling 2 1000 watt air cooled hoods, taking air from the basement through the hoods and back in the basement, then have a 200 cfm fan and filter for the exhaust of the tent?

Or have the fan pulling air through the filter, then the 2 hoods and out the tent?

The tent is in the basement, which has good air exchange with the outside and the temp is around 65 year round.

Taking in all the graphs and info gets a little confusing. Thanks

 

[CrazyCanuck75]

Every situation is a little different but the purpose of this post is to show you that cooling your lights, separate from your exhaust is the most efficient way to cool your room or tent. I was originally going to go with a big ass fan and filter for my tent until I read this thread. If you don't get the graphs, etc., look at them and read until you do. It will save you a lot of time, money and frustration in the long run (noise too).

 

[echo_chamber]

Anybody have any experience with these?

http://www.harborfreight.com/8-inch-portable-ventilator-97762.html

Low speed is 1400 CFM and High Speed is 1575 CFM. For $75? Assuming this thing can handle running 12 hrs/day, how many 1K lights would this cool? Doesn't look that hard to modify for our applications. Think I may give it a try.

Those are Axial fans so they are best for straight runs.. wont pull air thru bent ducting very efficiently, you'll need centrifugal fan for that.

 

[bentom187]

hello guys, im designing a small indoor grow, and i need your help, ive got this tent
http://www.htgsupply.com/Product-Grow-Tent---Size-S-22-x-36-x-63---Silver-Lined.asp
and getting this fan filter combo
http://www.htgsupply.com/Product-A-GrowBright-4in-Inline-Fan-&-Carbon-Filter-Combo.asp#

the problem is i was never good at math,and cant make sense of the formula on page one
like where did the 3.16 come from, im just not sure and is that a multiplication symbol after it....so i was woundering if somone could re-write the formula in simpler terms,or explain where these numbers came from.
also the acpm & mpac, seems a bit confusing .

my tent is 3ft long x2ft deep x 5 1/4 tall
my fan is rated 170 CFM

by red's 2nd example with a 400watt (wich i plan to use) i might have a bit to much since the grow space in the example is bigger than mine with a 126CFM fan and is stated to be overkill.

id like to get this down for future aplications your help is greatly apreciated.

 

[5th]

Without Red's guide and a lot of input from others I would have quit trying to grow my own awhile ago...I've kept it very simple and haven't had a heat/smell issue since my first cab. I'm far from a pro but this is my two cents...

A spot with say....3x2x5 is 30 cubic feet right? Well you need to exhaust that space twice in a minute right? (right) So your intake (provided its passive) needs to be double the size of your exhaust. So you have a 4" exhaust fan rated for 98 cubic feet a minute, you'll need a 8" intake (minimum)...well since you only need exhaust of 60 cubic feet a minute your golden right?

Nope.

You stick a scrubber on there...commercial or homemade...your messin' with stuff. Your exhaust is no longer rated at 98 cubic feet per minute...more like half that (filter dependant) so your not getting proper flow...your not exhausting heat...your causing tons o' problems.

Ensure your intake is more then sufficient, buy a fan rated for much more then you need, buy a contoller to adjust the fan speed so things are in check...and you should be fine.

 

[5th]

carbon filter|fan|air-cooled hood -----> exhaust outside.

I'm gonna suggest, air-cooled hood/filter/fan------>outside

It'll keep your glass cleaner thus allowing more lumens to get to your plants. Scrubbers, bought or homemade always leave fine particles on your hoods glass.