Building Growroom

Hello everyone,
So I am Finnising up my room build and would like some input on the ventilation system I want to do. I have one large room that I broke up in to 3 smaller rooms 2 veg 1 flower . The room is on the Sw side of building extior walls . Each room room is 4x4x8 with a 2x4x6 hallway running across the front of them . I have a window I am turning into the intake . It will have a 12x16x1 HEPA filter for the opening into an 32x16x5 plenum and I have 2 12" take offs hooked into 2, 8" insallated ducts the one will be run along the E. Wall throughout each room . There will be a takeoff to a 6" cool tube 600 HPS in each flower room and a 4" at the end if the run into the veg room. The second 12" take off will have a 8" insallated duct running under the floor that is build up 12" to allow with a 6" take off into each room.
For the return I have 8" insallated duct running along the hallway cealing . The duct has a take off into each room to connect the lighting . There is a 10" hurricane fan @1120 . I was thinking about making an y connection at the lighting takeoff for a4" room air exchange in each room. I’m not sure if that is too much stress on the fan . Thanks for the help

WOW, that is a lot of info!!
My first grow, last year, was a big learning curve for me.
I started with a 200cfm fan mounted in the ceiling and it was not enough. I had to turn the lights down to control heat and use air freshener for the odor when I had company. Pain, pain, pain.
This year I am going with a 400 cfm, 6" fan in the ceiling with my 4" remaining as back up.
Odor was as big a problem for me as heat was. I guess my advice would be to go with your idea with the thought in mind that you may need to add more later!!!
Wish I could be more help but there it is!

Lol thanks… I have had 2 cabinet grows and and outdoor as well… I started the room just under 2 years ago and it just was more problem then not … didn’t have it vented only one flower room running … and with that I plan on using a 4 bucket hydro farms Rdwc in each flower room . Want to get this done right this time so I can focus on mastering my grow . Thanks for the input

With a SW facing corner room you will have alot of heat.

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I live in the NE so I’m not to worried about to much heat … do u think it will help with keeping the room warm when it’s 0-15°f out? I figure if I need to cool the room in the summer I would get a water chillers for my buckets… I have a room on the opposite side of the hallway I plan on venting into and use that room as my prep room with my res of water

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The pic of the plywood is where the 2 12 to 8 intake will be… I trued to show the hallway and how deep the rooms are

I think @Countryboyjvd1971 would be able to help you here…CB, could you go back to the top and help this grower with your expertise, please?

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Having the three rooms I’m not sure a 4 inch will be enough for that fan but I am not 100% sure I think you’d be better off going with a 6 inch or 8 inch size a fan the only reason I think it will work it’s because you have three rooms but I’m with @FloridaSon you should talk to @Countryboyjvd1971 he is a great man to have around to ask these questions hvac guy but your little room looks fabulous keep up the good work man good luck hit me up if you have any questions

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Will do @FloridaSon thanks
Each room is 128 cubic feet
You’ll want to pull max 100 cfm since you would exchange air once every 1.5 minutes
Your duct work should be size for you cfm requirements with a fan moving over 1000 cfm you’ll be pulling a ton of air from rooms and may find it hard to maintain humidity levels
Depending on your climate
A few pictures of duct work if possible would help me determine what you have going on @BuffaloSoja
I read the description of your lay out
Maybe draw a diagram and post that ?
With duct work that’s too large you will lose static
pressure which actually slows down air flow FYI
I did read your post fast I’m at work now
Tag me later if you do post pics and or a diagram of lay out
I’ll be happy to help you out
Happy growing


Hey @Countryboyjvd1971 thanks for the help. So If your profile is correct we share similar weather conditions. I was thinking on using a speed control on the fan to pull at a proper speed . Here are so digrams I through together the intake is from outside and the ventilation will into an adjoining room I’m going to use as my work space .

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Looks good and yeah my profile is accurate bro I’m about half way between NYC and Albany if that helps
Diagram looks good :blush:
Speed controllers are great :+1: idea
Are you planning on bringing in fresh air ?
Or are you just going to have passive returns in rooms
I have a fresh air intake I use but close it off in the winter and use passive vents but once it starts to warm up day time temps above 50 I open it and allow good fresh air in from outside I have a tent basically around my tents
I built a temp grow room out of heavy black plastic to contain humidity and temps and do plan on building actual walls one day my grow is in my basement so temp walls are fine for now lol

@Countryboyjvd1971 thanks I’m a couple hours west of Albany. I just planned on having it a passive intake from outside air… not sure how I would do that… but I like the idea I’m not sure how I am going to be extracting the room air room 2 and 3 the return would be hooked directly to the lights . Room 1 would just be open due to the T5 I plan on just using black plastic as a door to separate each room for the other. Could I come off my 8" return with a Y in each room ? One for the light and one for the room air ? . I also wanted to hook something up where I’m using my extracted air to flow through a drying cabinet I will have in my work area . I was going to use a 4’ line for this

I would also like to add that the room /rooms are located in a larger non heated or insallated building I will be storing large amounts of R/o water in the work area due to not having a source readily available… thanks guys …
Oh and here’s some NYC Desiel I Finnished up


Nice buds brother and cool so your probably a week or two behind me in temps since your farther north then me
Yeah you could use a y connection if needed
Is your set up in your basement?

Lol no but those bud pics were😎… it’s in an upper part of an out building I have on my property

Ok so I want to start on the raised floor and passive intake that runs underneath it. I will have 8" round insallated duct running under it. With a takeoff​ into each room. Do u think that will be enough or should I make it a 6" … I have the top half of the window box that I can put an 8" duct off into my storage room. / Same room I exhaust into as ND I will put a Damper there to open and close it for summer/ winter. I will just shut the window to keep the air mostly recerulating

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I think a 8" will be more than enough bother eight in round duct is good for about 200 cfm
So you pull plenty of air threw it
Sounds like your off to a solid start brother

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So I meant to say I have the 8" as a main trunk and was going to reduce it
to 4" . ( Thinking it would allow for a more even air draw in all 3 rooms,
) but with your response I’m guessing to small and should do at least 6" .
Or am I over thinking it and just make each room with the 8". Also do u
fallow me on the intake box , and putting the 8" in the top half of the
window to open and close the window glass so the air comes from the same
room I exhaust into. Would one be enough to support a closed style system
during the cold months,?
Thanks a ton for all the help

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Ok I’m following I would definitely use 8 as main line and use four inch pipe for each room 4 inch is good for about 100cfm or you could use 6 inch and use damper to balance out the air flow ?

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