Tutorial Ventilation 101

[Tactical Farmer]

I originally planned to run the filter first but after doing the paintshop drawing there looks to be alot of areas where stinky air could sneak in gaps & reek out the attic / outside.

The intake should be pretty strait run but also pretty long.

These Panasonic fans are 6 IN so finding proper connectors for large duct may be an issue.

Just want to do it right the first time - even if more money needs thrown into it.

THANKS ALOT GUYS - This is tricky to get a handle on it, good drawings help alot.

 

[hoosierdaddy]

I agree that the intake would be best to remain passive, but I would stick with the 12" if you already had plans for that. Never too much air.

The filter should be at the beginning of the run, and many do have them on the floor, but it is more efficient if they are suspended from the ceiling at a high point where heat goes. Sucking from the floor only takes out the coolest air in the room.

If it were me, I would put both of those inline fans together, and I would hang then IN THE ATTIC suspended from bungy cords to take away the noise. This will allow you to have all the CFM and pull force you would need. Don't put a fan at the start of any run. Anything at all downstream happens, and you could be pushing out unscrubbed air through every nook and cranny it can find to get out, and it will find them.

Also, when you duct from your roof stack use insulated ducting from there to the ceiling of the room. Don't let the attic heat up the air on the way in. You could save and just use regular duct everywhere else.

Always pull the air and try to never push it.
A scrubber in the line is more efficient if it is being pulled from instead of blown into.
A scrubber down low sucks up precious cool air.
Lights will allow leaks, so duct tape (or aluminum tape) the edges up.

If you use 12" in and 6" out, you should be golden.
And I would reconsider the intake damper. Even a non-powered one-way damper can stick and cause you mucho problemo. Is a damper even needed? I say no. Worst case it would need a filter (panty hose...furnace filter?) to keep out bugs and dirt.
Unless you are planning a sealed type room, a damper is not needed, IMO.

 

[Tactical Farmer]

Back from Lowes - Went with 12 in insulated intake & 6 in insulated exhaust.

The 12 in materials seem crazy large - Go BIG or go home to mommy...

Also got pond liner for the entire floor - reflectix for walls - lumber - foam - etc - etc.

DAMN - Looks like I need to install a different roof vent ( pretty much backwards to what I need.

3 are 6 in standard type & 1 is a 10 in turbine spinning vent.

They dont happen to make a reverse turbine that the wind will push air in do they ?

 

[hoosierdaddy]

lol...never thought about those.
Yeah, they do operate to suck air out of the tube. If your fans were off, it could in theory draw some of your stank air up to the intake on the roof. But I wouldn't think any sort of occasional thing like that would be an issue at that height. It sure isn't going to restrict the air from coming in when the fans pull on it. It would take a sharp cookie with a good eye to figure out that your spinner is spinning backwards! lol...

Man, I envy you. I love putting rooms together.
And hell yes, go big. I like your style.

 

[Tactical Farmer]

Your more than welcome to come & help, I sure do need it. Got some God Berry, Green Devil, & some White Widow hash - hell I will even get us some pizza & red bulls.

i spend tons of time thinking it though & it ends up taking forever.

got a bathroom FULL of 2 footers that need a nice home quick so im stressing, THANKS for the quick outstanding help..

Humm - My brains single cylinder is really revving now. lol

it would be ideal to get that turbine roof vent to spin the opposite direction for the intake.

would it still be considered "passive" if the wind helped ? lol

wonder if I could just invert the fins on it to blow in ?? muhaahaahaa

that would be sweet to just use the wind for both - free air exchange.

Regardless the roof vents are the weak link right now - major room mods start tomorrow.

Ill take some pics if theres interest - thanks ALOT fellas..

* No one seems to make a reverse roof turbine vent & it dont look like it can be modified.

Inspiration: http://www.youtube.com/watch?v=ff5sW8A1pMc&feature=related

 

[Tactical Farmer]

Damn again, After watching a few of those roof vent vids im now scared to death to use one even in the proper direction.

Imagine on a calm day - everyone on the street that has one is at dead stop & over at the gardening dudes house, there spinning like a top & different directions.

Damn it ALL - Lets just kick this Revolution off now, im so tired of this crap...

 

[hoosierdaddy]

I seriously doubt you have to worry one bit about that roof vent. I wouldn't think about it any more. It will not force air in or out to any degree at all. And it won't be doing things that anyone will ever notice. It really only helps to keep a flow going from a raw air attic. It isn't forcing much at all. It is basically just reacting to the air flow being placed on it.

Again, my main suggestion would be to have the scrubber at the start, and the fans at the end. Don't push air if you can help it, pull on it always. And the intake damper would be something I would not trust and wouldn't use at all. Do you really need it? Are you going to seal up the room for Co2 introduction? If not, a close off is not needed.

 

[kimirk]

ke kit mi consigli di montare sulla mia grow homebox L...100x100x200h??

 

[kimirk]

ke kit mi consigli di montare sulla mia grow homebox L...100x100x200h??

 

[Tactical Farmer]

Yep - got some real doors, no more fakkin' with rigged up chit.

Got alot more to go but the worst is behind me.

Had to put the holes here as the 2 layer of ceiling beams left no other option but it will work fine.

I know its not optimum but decided to place one of the fans in the middle of the lights, it fits perfect, SUPER quiet & still has some decent force at the end of the duct at the attic vent hole even with the carbon filter hooked up.

Should work great to cool the hoods by itself & the second fan placed in the attic @ the exit should get a nice vacuum going.

Im working on a homemade intake filter (super dusty outside) if this bucket setup doesn't work them looks like on of those $200 12in hepa duct filter will have to do.

Opened up one of those super furnace filters for the fabric & going to simply hook the bucket to the duct & rubber band the filter to the bucket.

The 12 in duct connector fit on the top of the bucket great, siliconed it & duct taped it for a clean airtight seal.

Thanks

 

[Fresh8686]

Quick question for those in the know. For two spaces, one at 54 cubic feet and the other at 72 cubic feet would it be overkill to have a TDS-200 mix vent fan pulling air from a Can 33 carbon filter in each room? The lights will be on a separate straight run cooling system with a TDS-125 blowing air on a 400w hps in an air-cooled hood (which might be overkill too, so if it is please let me know). Also, should i have the TDS-125 near the intake blowing the air on the light or instead put it on the exhaust side to suck the heat out of my grow cab?

Appreciate the help, I've got a basic understanding of how I want things to work based on reading this thread, but when it comes to sizing specifics im not to sure about everything.

 

[big ballin 88]

You could use that TD 200 to pull air from both the tooms if your using a seperate cooling system for your lights. Can you make a box to draw air through? This box would connect both rooms together by ducting and than lead up to the carbon filter.

Than again this is what i would do. It also depends on your locations and your outside temps.

 

[Fresh8686]

You could use that TD 200 to pull air from both the tooms if your using a seperate cooling system for your lights. Can you make a box to draw air through? This box would connect both rooms together by ducting and than lead up to the carbon filter.

Than again this is what i would do. It also depends on your locations and your outside temps.

Thats a pretty good idea and might be an option for me, but right now I was planning on each space being completely separate and self contained so I could have a little more flexibility with their placement. I might not necessarily have enough room to place them side by side, depending on how the final lay-out of my area works out (moving into a new house, so the arrangement of things are kind of up in the air at the moment).

Appreciate the input.

 

[puff adder]

I have one room set up similar to this, although instead of the intake coming from the roof, I plugged and knocked out the central heat/AC duct in the floor, opening a hole to under the house, which acts as a passive intake. Cold air from under the house is sucked into the room. I built a filter box and placed it over the hole.
Using the cold air from under the house is very effective.

Damn - I see what you mean, daahhhh...

This seems like it would work better without having to buy another fan ?

The room is pretty sealed - so with the pressure concept this (passive intake) should cause a vacuum in the room causing fresh air to be forced down the 12 in duct at a good rate ?

Looks like I will need a 12 in damper to keep dirty air from sneaking out the intake if the exhaust is off.

 

[noost]

Need to vent...

Need to vent...

and dehumidify. Not sure how to set this up for Humidifier/heatAC/lights.
-6x6 room Have 4" fan and 1000w 4" air cool hood and soon will be using 2 600W 6" instead.
-all outer walls go outside (open air)
-Dashed line represents a wall I will build to separate veg/flower.

I looked at the setup pics and I will be #4 2 stage

1.Where does the intake air come from? Outside, another chamber?
(for both the room and the light)
2.Where would the dehumidifier/heater go?
3. How would you set this up?
thanks

 

[noost]

pic

pic

pic

 

[miniweiz]

im thinking of doing the ventilation with cooltube and scrubber method for my pc grow box. i dont think theres room for intake on both sides for the grow area but if i adjust one side to have 2x intake and the other side would be just an exhaust vent would that be alright or would it be bad for the plants/ventilation system?

 

[KolorBlind]

Great Thread!!

Great Thread!!

Hey RG

Thanks so much for this thread man, I come back to it every time for ventilation tips and charts. I have got my closet all gutted and painted and I will begin constructoin tomorrow. Based on this thread, here is what I have come up with for my intake and exhaust:

Total Growspace Dimensions: 62.5" Wide, 20" Deep, 96" Tall
The Breakdown:
Flower = 62.5 x 20 x 62
Veg = 62.5x 20 x 22
Utility = 62.5 x 20 x 11

My Fan: 4" S&P TD-100x (Currently set to 100cfm, will be switched to 135)

My Lights (for now): 250w HPS for Flower, Three 42w CFLs for Veg


The basic plan is to build a false wall with two 8 foot tall doors that swing open, using the closet walls for the sides and back of the "cab". There will be 2 shelves, with holes drilled on opposite sides for ventilation.

I will drill holes in the back wall of the closet, then cut out two 4x10" (maybe 4x16") holes in the bedroom wall just behind the closet so I will be pulling air in from that bedroom.


My original plan was to drill four 4" holes everywhere the air needs to pass through. After searching hardware stores, I realized that it is hard to find the true 90 degree 4" elbows, and the 2" elbows are much more cost effective. Based on this thread, I think I need eight 2" holes at each point the air must pass through. Seems like overkill to me so I wanted to be sure since I will be drilling the holes tomorrow morning.

I have attached a couple pictures from my most recent sketches in google sketchup so you can get an idea of the setup. The air will basically come in at the lower left against the back wall, cross over to the right side of the bottom shelf, then across the veg area through the left side of the top shelf, then across the utility area, through the scrubber and up through the 4" hole that goes into the attic where my fan is hung from bungees. The fan will be pointed towards the gavel at the end of my attic with no ductwork after the fan.

In the sketches I have 4" holes and PVC, but I plan on going with 2" I just havent modified the sketch. I will also only have one 250w HPS until winter, then I will add my 150. The top shelf will have no PVC elbows because I dont have to worry about light leaks at that spot. I will also have a cloner, 12 4x4" pots for veg, and 2-4 4x4" pots for moms on the second shelf instead of the setup in the sketches.


Let me know what you guys think. If eight 2" holes is what I need, then tomorrow I will go buy 24 2" PVC elbows and put my 2&1/4" hole saw to work.


Thanks a bunch! Here are the pictures
KB

 

[gdbud]

A 4" hole has an area of 12.5 square inches and 4 - 2" holes have an area 12.5 square inches and 6 - 2" holes have an area of 18.8 square inches. Which would give you 1-1/2 times the area of a 4" hole. I would start with 6 - 2" holes.

 

[KolorBlind]

Thanks for the reply gdbud

I still havent decided on 2" for sure, I am still playing around with the idea of 4" simply because I should have the room. It just means using my 4" hole saw (since Im too cheap to drop $40 on a 4-1/8") and boring each hole out with a file. Or I would have to rely on glue to hold the PVC elbows to the wood shelf, which I dont like at all.

Sheesh, this is easily the hardest part of setting up a grow space. No matter what I do its always the part of every project that I get hung on for the longest.

What do you guys think about the setup overall? Any ideas or obvious flaws? Think the air will be able to make the multiple transitions AND go through a scrubber while keeping temps down?


Thanks
KB