Venting an odd shaped room (not sealed) advice please

GrowingRx

GrowingRx

Active Member
Sorry to be a little winded, but if you make it to the end, i send my gratitude. Big project in the works and im sure I will have more questions over time. Looking for some advice from folks who have much more experience than myself.

I have an odd shaped room that I am trying to vent. Due to the layout of my house, and some other factors including some medical issues, having this space as two rooms for veg and flower doesn't quite work at this time. So my option now is to build one large room and use it for a whole lotta fun! I understand i will not be using every sq ft to its advantage but im looking for a space that i can go into and be comfortable moving around in.

The space that I am trying to vent is 8' (left to right) 6' (front to back) 7' (tall) now... where it gets fun, to the left of this space i have another section that is an additional 6' (left to right) 5' (front to back) but only 4.5' tall!

So my questions are;
-Do i vent the space as one entire room with a single large exhaust?

-Do I vent each section as if it were its own since as the heat will rise differently in each space? I was planning on having fans blowing air from the small section toward the large section if this would help. But this could also leave an opening for an easy conversion to two rooms later.

-From my research, it would also be advisable to run an active intake with this size of a room. Would piping an active intake into the small space and have the exhaust come out the large room at the opposite end eliminate the need to "dual vent" or would i be best doing both, dual vent and active intake?

-Normally when using a passive intake you would want your intake to be twice the size of your exhaust, would using an active intake eliminate the need for this?

to make things even more interesting i will be looking at having about 18-20 feet of ducting, im planning on using rigid for as much of it as possible and flexy bits in spaces that require any sort of curve that a 45 degree bend wont fix so i can swoop instead of doing 90 degree bends

I currently have two 6" vortex s-line fans (347cfm) from my old setup. I dont feel that these will be enough to do both rooms as they were on max in a 3x3x6 space but with flexy ducting, not sure how big of a difference the rigid vs flex will be.

My current ideas running in my head are
dual vent with two 6" exhaust with passive vents (doubt it will be adequate, i dont like running an AC if i can help it so more is better i suppose)
dual vent with an 8" and a 6" with passive vents
same as above but 6" active vent


if you have made it this far, you are a God. thank you. i look forward to being schooled.


some of you may be wondering "what is this nut job doing with such a large space and not splitting it? how is he planning to fill the space? read on friend!

I plan to be starting most stuff by seed.
i favor using single pot dwc as my growing method. i will be using 14 gallon totes on a wheeled platforms. each tote will have its own scrog net attached to itself. each net will be 2'x2'.so everything is modular to an extent. I will be able to pull my plants out of the lower space and work on them in the taller space.

while i have a section of plants growing up and into their nets, on the other side of the room i will just have LST trained autos in some dwc totes also that i started at the same time. With my recent experience growing with a scrog, my auto plants (provided they are not long flowering times) should be done roughly around the time my scrogged plants are ready to be flipped.
a couple weeks before flip time is ready i will take some clones from each of the scrogged plants and do a small SOG in a 2x4 flood table where the autos have just been harvested from. The flood table is new to me, never used one before so i wanna give it a go after i get some autos done and have something to smoke while i fool around with a new setup.


alright, i think thats it for now. thanks again all, this place has been a great help so much already. :)
 
SheeshM

SheeshM

Well-Known Member
I can't school anyone but to size your exhaust, you can find formulas online that start with your total cubic ft and add more capacity for filters, HID lighting, and length of exhaust ducting. HID or LED lighting is a big factor too. A 20' duct run may require booster fans too but hopefully the guys who know this stuff will chime in.
Try this link: https://bigbudsmag.com/calculating-cfm-exhaust-fan-marijuana-grow-room/

I'm trying to think of a good use of the 4.5' tall space. If you can sit and roll a chair in there without too many dents in your head, maybe use it for storage and germinating / cloning. Your scrog on wheels is great but do you have the headroom to flower plants in the small room? Whatever you decide, it sounds like a fun project. I'm getting too old and broken to grow in a tent much longer and plan on building a room someday. Keep us posted!
 
GrowingRx

GrowingRx

Active Member
SheeshM said:
I can't school anyone but to size your exhaust, you can find formulas online that start with your total cubic ft and add more capacity for filters, HID lighting, and length of exhaust ducting. HID or LED lighting is a big factor too. A 20' duct run may require booster fans too but hopefully the guys who know this stuff will chime in.
Try this link: https://bigbudsmag.com/calculating-cfm-exhaust-fan-marijuana-grow-room/

I'm trying to think of a good use of the 4.5' tall space. If you can sit and roll a chair in there without too many dents in your head, maybe use it for storage and germinating / cloning. Your scrog on wheels is great but do you have the headroom to flower plants in the small room? Whatever you decide, it sounds like a fun project. I'm getting too old and broken to grow in a tent much longer and plan on building a room someday. Keep us posted!
Click to expand...
thanks for your reply, all I've been seeing is tumbleweeds. lol
as for the calculation formulas, I has been doing those over and over and came to a conclusion that im going to lose about 60% fan efficiency.
I was curious about the booster fan idea, but i wasnt sure if the naturally lower speed of a booster fan installed somewhere downstream would cause any sort of back pressure on the actual exhaust fan. This IS an idea i have considered.
So far im leaning toward venting each section as its own, im thinking of using the vortex s-line 6" for the small section and i just purchased an 8" s-line for the large space. Im also thinking that using an active intake will allow me to make a filter box using a furnace filter and also i wont have to cut so many holes in my wall. Im looking to move in the near future so this space needs to be "dual purpose" for when I leave it will be a finished laundry room with storage. ;)

I do plan to use the smaller section as a sort of storage, i can tuck large items out of the way, dehumidifier, humidifier, ect. and have it all blown over with a tower fan or wall fan.
Im pretty confident i can flower a scrogged setup in that space. my lights will be around 14-16" from my plant cannopy. I just got out of a couple tents where i only had 3' of growing space once exhaust, lights, and dwc bucket was factored in. still had room to spare! I plan to only flower indicas under there anyway lol. I have 12 crecer quantumx 200 lights that i will be using. Lower wattage on each light but the heat they put out is minimal (i can hold my hand on the back after it being on for 10+ hrs) Ill be using an apogee-mq500 to dial in my light spread. Im going intense with these, but im happy with the results i just had with only 1 over a 2x2 area pulling 6oz from 200w. I want to try 2 of these over a 2x2 canopy. ;)
i feel you on the old and broken thing... im getting out of the tents because its too difficult for me to manuver them. I just had hip surgery not too long ago, hence the whole modular thing and not wanting to veg in such a low height space. Eventually when I move ill be growing vertically with a veg space to feed my flower room. But as cannabis growing goes, we make do with the unique spaces we are given.
 
GrowingRx

GrowingRx

Active Member
zzbudzz said:
In my honest opinion that 4.5 ft tall room is gonna be a pain in the ass for you.
Click to expand...
in a way, im thinking the same. the entire space needs to be done regardless so that when we move out its going to be a "finished laundry room w/storage" I figured why not give it a shot using it before its completely a waste of space holding equipment and dust. lol
The good thing is that down the road i could put a partition wall there if i choose to, but being in both spaces, pretending there is a partion wall there while growing, it just makes it all very cumbersome with what ill be using. I love hydroponics, but damn the equipment can be large!
 
Z

zzbudzz

Member
GrowingRx said:
in a way, im thinking the same. the entire space needs to be done regardless so that when we move out its going to be a "finished laundry room w/storage" I figured why not give it a shot using it before its completely a waste of space holding equipment and dust. lol
The good thing is that down the road i could put a partition wall there if i choose to, but being in both spaces, pretending there is a partion wall there while growing, it just makes it all very cumbersome with what ill be using. I love hydroponics, but damn the equipment can be large!
Click to expand...
I understand man, I have had my on hurdles to deal with that I didn't anticipate. I built a cabinet that is 2ft deep 4ft wide and 6 ft tall. That 6ft height has given me some problems with lights and filters stuffed in there.
 
M

m99smith

Well-Known Member
GrowingRx said:
Sorry to be a little winded, but if you make it to the end, i send my gratitude. Big project in the works and im sure I will have more questions over time. Looking for some advice from folks who have much more experience than myself.

I have an odd shaped room that I am trying to vent. Due to the layout of my house, and some other factors including some medical issues, having this space as two rooms for veg and flower doesn't quite work at this time. So my option now is to build one large room and use it for a whole lotta fun! I understand i will not be using every sq ft to its advantage but im looking for a space that i can go into and be comfortable moving around in.

The space that I am trying to vent is 8' (left to right) 6' (front to back) 7' (tall) now... where it gets fun, to the left of this space i have another section that is an additional 6' (left to right) 5' (front to back) but only 4.5' tall!

So my questions are;
-Do i vent the space as one entire room with a single large exhaust?

-Do I vent each section as if it were its own since as the heat will rise differently in each space? I was planning on having fans blowing air from the small section toward the large section if this would help. But this could also leave an opening for an easy conversion to two rooms later.

-From my research, it would also be advisable to run an active intake with this size of a room. Would piping an active intake into the small space and have the exhaust come out the large room at the opposite end eliminate the need to "dual vent" or would i be best doing both, dual vent and active intake?

-Normally when using a passive intake you would want your intake to be twice the size of your exhaust, would using an active intake eliminate the need for this?

to make things even more interesting i will be looking at having about 18-20 feet of ducting, im planning on using rigid for as much of it as possible and flexy bits in spaces that require any sort of curve that a 45 degree bend wont fix so i can swoop instead of doing 90 degree bends

I currently have two 6" vortex s-line fans (347cfm) from my old setup. I dont feel that these will be enough to do both rooms as they were on max in a 3x3x6 space but with flexy ducting, not sure how big of a difference the rigid vs flex will be.

My current ideas running in my head are
dual vent with two 6" exhaust with passive vents (doubt it will be adequate, i dont like running an AC if i can help it so more is better i suppose)
dual vent with an 8" and a 6" with passive vents
same as above but 6" active vent


if you have made it this far, you are a God. thank you. i look forward to being schooled.


some of you may be wondering "what is this nut job doing with such a large space and not splitting it? how is he planning to fill the space? read on friend!

I plan to be starting most stuff by seed.
i favor using single pot dwc as my growing method. i will be using 14 gallon totes on a wheeled platforms. each tote will have its own scrog net attached to itself. each net will be 2'x2'.so everything is modular to an extent. I will be able to pull my plants out of the lower space and work on them in the taller space.

while i have a section of plants growing up and into their nets, on the other side of the room i will just have LST trained autos in some dwc totes also that i started at the same time. With my recent experience growing with a scrog, my auto plants (provided they are not long flowering times) should be done roughly around the time my scrogged plants are ready to be flipped.
a couple weeks before flip time is ready i will take some clones from each of the scrogged plants and do a small SOG in a 2x4 flood table where the autos have just been harvested from. The flood table is new to me, never used one before so i wanna give it a go after i get some autos done and have something to smoke while i fool around with a new setup.


alright, i think thats it for now. thanks again all, this place has been a great help so much already. :)
Click to expand...
Seperate the rooms use the smaller one for seedlings and veg and use the bigger one for flower to get a perpetual grow
 
GrowingRx

GrowingRx

Active Member
zzbudzz said:
I understand man, I have had my on hurdles to deal with that I didn't anticipate. I built a cabinet that is 2ft deep 4ft wide and 6 ft tall. That 6ft height has given me some problems with lights and filters stuffed in there.
Click to expand...
ha! i know exactly the feeling. I was in two 3x3x6 tents before this. There were some things i didnt take into cinsideration with them at first... like needing more space around the tent so you can work inside it... oops. leaning into a small space just isnt for me either. I need one of those spaces that you see with the rows of plant beds, where you can walk all the way around them and work on them. Thats the dream. I want the yield, but Im totally into this build for the ergonomics. I want to finish the grow and say to myself "that was fun, lets do it again" instead of "my god that was a lot of work and i feel like a contortionist"
 
Renfro

Renfro

Well-Known Member
GrowingRx said:
-Do i vent the space as one entire room with a single large exhaust?

-Do I vent each section as if it were its own since as the heat will rise differently in each space? I was planning on having fans blowing air from the small section toward the large section if this would help. But this could also leave an opening for an easy conversion to two rooms later.
Click to expand...
Good air circulation to minimize micro climates and one exhaust fan and perhaps one filtered intake on the opposite end of the room. In my large odd rooms I just use the filtered intake.

Always good to oversize the blower and use a variac to slow it. this gives you more power if you end up needing it in the future and it runs a lot quieter at reduced speeds. Larger duct flows much better too. Galvanized snap seam FTW.
 
GrowingRx

GrowingRx

Active Member
Renfro said:
Good air circulation to minimize micro climates and one exhaust fan and perhaps one filtered intake on the opposite end of the room. In my large odd rooms I just use the filtered intake.

Always good to oversize the blower and use a variac to slow it. this gives you more power if you end up needing it in the future and it runs a lot quieter at reduced speeds. Larger duct flows much better too. Galvanized snap seam FTW.
Click to expand...
*kneels*
I appreciate you stopping in to throw your wisdom down on my thread.
I picked up a vortex s-line 8" (711 cfm) do you think this would be adequate to vent both sections? (471 cubic feet) or should i send that back and step it up to the 10"? i feel having a 10" pipe might be a challenge for my run though.

my running plan was to have a filtered 6" intake coming into the lower space, with a large exhaust at opposite end on the taller room. I was debating adding the 2nd 6" as an exhaust in the short space but felt it might be pointless. now if i were to have a couple fans on that end blowing out toward the large space i think it would do much better.

I have never run with an active intake before, how exactly do i know how much air to bring in? I like to keep a little neg pressure to make it just a bit more difficult for pests to make my place home.

since i have a large exhaust run it has me thinking about restrictions. common sense tells me if one filter has more surface area than the next, choosing the larger one would result in less restriction. Should I be looking for the largest filter i can accommodate? Is it okay to have a filter that is rated for say, 900cfm and your fan only pulls 700cfm? or is it best to size them up in cfm range instead of physical size.

thanks again, appreciate the help.
 
Renfro

Renfro

Well-Known Member
GrowingRx said:
I have never run with an active intake before, how exactly do i know how much air to bring in?
Click to expand...
Use a dust shroom on the intake to filter it. Use a temperature controller to cycle the intake as required to hold canopy temps, this will compensate for varying ambient (outdoor) temps. Use a good carbon scrubber/s recirculating the room air to kill odor so your house doesn't reek.
 
Renfro

Renfro

Well-Known Member
With carbon filters I get the biggest one I can. It will last longer if nothing else. Each of my flowering rooms has two 12 x 48 Phat filters with 12 inch Vortex blowers. They recirculate room air as scrubbers. I use adjustable elbows to aim the output air flow so it goes below my lights above the canopy. So I need less fans in the rooms with those loud fuckers running. If one goes off like a tripped breaker it isn't long before the house starts to reek if I am in flower.
 
Renfro

Renfro

Well-Known Member
Definitely setup to run at night when the outside air is cooler. If you live in like florida or somewhere humid then buy a minisplit and a dehu and forget the ventilation.
 
GrowingRx

GrowingRx

Active Member
Renfro said:
Use a dust shroom on the intake to filter it. Use a temperature controller to cycle the intake as required to hold canopy temps, this will compensate for varying ambient (outdoor) temps. Use a good carbon scrubber/s recirculating the room air to kill odor so your house doesn't reek.
Click to expand...
that dust shroom is WAY cool! thanks for the tip. how often would you have to replace these? i was planning to just build a box and use furnace filters for a home HVAC.
so that active intake actually doesnt need to be running all the time like a passive intake always has air coming in?
 
GrowingRx

GrowingRx

Active Member
Renfro said:
With carbon filters I get the biggest one I can. It will last longer if nothing else. Each of my flowering rooms has two 12 x 48 Phat filters with 12 inch Vortex blowers. They recirculate room air as scrubbers. I use adjustable elbows to aim the output air flow so it goes below my lights above the canopy. So I need less fans in the rooms with those loud fuckers running. If one goes off like a tripped breaker it isn't long before the house starts to reek if I am in flower.
Click to expand...
i never actually though about using my exhaust fan as an air mover inside the space to eliminate the use of fans. thats a great idea!
im still concerned if an 8" would do for exhaust or not. :-/
 
GrowingRx

GrowingRx

Active Member
Renfro said:
Definitely setup to run at night when the outside air is cooler. If you live in like florida or somewhere humid then buy a minisplit and a dehu and forget the ventilation.
Click to expand...
unfortunately, due to my work schedule my rooms will have to turn on at Noon. Thats the only schedule i can have time to work on them while lights are on. Do you recommend a green working light for lights off times? ive been using a green headlamp with what seems to be no ill effect.

if i were to run the minisplit, wouldn't i need to run co2? that's my understanding of a sealed room. I dont know enough about how sealed rooms work to really feel comfortable going that way. unless its a lot easier than im thinking.... honestly, not having to run ducting would be sweet and VERY convenient in my situation as my exhaust pipe needs to be low-ish to run under a bulkhead.

How do I go about sizing up a miniplit for that space?
 
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