4x8 aircooled hoods - ventillation help NEEDED!

G

GP Rust

Member
Hi everyone. Hope you guys and girls can help me out.

I have an 8x4 tent that I got for flowering . I am using 2x600w hps with aircooled hoods. My tent will be unsealed - as I do not have access to co2 control.

I plan on exhausting into my attic as I am not concerned about humidity or temperature as there is good air flow in the attic.

My question is whether I need to exhaust the lights on a closed loop and the tent seperately or if that is unecessary. I would like to use 1 centrifugal fan to suck the aircooled hoods and the tent at the same time.

Ive though of 2 ways to do this:

1) leave the one side of the aircooled hoodS open so that my tent and hoods are exhausted simultaneously (will the pull from the fan still be alright after the hoods).
2) use a Y-branch at the exhaust port and split the ducting between my hoods and a small piece that will hang in my tent . This way there is no obstruction of the hoods before my tent gets exhausted.

If i do option 2. I could run an intake for the hoods from outside the tent or also leave the one side open (similar to option 1) thereby using the tent as an intake.

Ps. I am happy to be using my fan to suck air and not blow.
Pps. I am blowing into my carbon filter which is in the attic - ive decided this is the best for me as well.
 
Ripped Farmer

Ripped Farmer

Well-Known Member
bazookajoe said:
why not just hang the filter and fan in the tent, then run the exhaust end of your ducting into the attic? (filter>>hood>hood>>fan>>>exhaust into attic) why is it best for you to blow into the filter in the attic?
Click to expand...

Do this. Pulling the heat off the bulbs directly instead of open air inside the tent is a much more efficient way of keeping heat down. Your fans will run much slower/less this way.
 
G

GP Rust

Member
bazookajoe said:
why not just hang the filter and fan in the tent, then run the exhaust end of your ducting into the attic? (filter>>hood>hood>>fan>>>exhaust into attic) why is it best for you to blow into the filter in the attic?
Click to expand...
Hey guys and thanks for the Replies. Thanks bazooka. Do you think it is fine to do like that? I worry that the exhaustimg will be less efficient - i am kind of worried about heat. The reason i put it after is to have clean uninterrupted sucking :bigjoint:, but I am not an expert amd would love input.

I have changed my opiniom of venting in to the attic as well...after experiencing a warm day I went up there and was not satisfied with its ability to remove heat. So I am planning on running it out through another room / window.

Will it be alright if the exhaust ducting goes for about 5m after the fan? I am unsure of if the distance will result in the air falling back in to the grow room / stagnating in the pipe...yet i somehow doubt this is physically possible :mrgreen: i got that OCD...

Thanks for tips. Here is some more info about my setup:

2x600w hps in 8x4 flower tent
1x630w cmh in 4x4 veg tent
Flower exh havent bought yet, veg exh is a Hit 125, which should exh the tent comfortable every 1 minute.
10000btu / 1100w portable single-duct AC.

Ive got this all in a room comfortably large enough to contain both tents with working space. Roughly 10x10 ft.

I do not plan on introducing co2 yet, because I have not found an economically feasible means where I live. So I cant seal the grow room, and want to duct the portable AC in to both my grow tents via a DIY splitter.
bongsmiliebongsmiliepeace
 
G

GP Rust

Member
Ripped Farmer said:
Do this. Pulling the heat off the bulbs directly instead of open air inside the tent is a much more efficient way of keeping heat down. Your fans will run much slower/less this way.
Click to expand...
Hi, thanks for the reply.

Do you mean the filter kind of slows down the exhausting of the tent itself...thereby allowing for a more 'continuous' exhaust of the hoods?
 
A

AKgrower29

Well-Known Member
I would limit the length of ducting as much as possible and if it is a straight run, rigid ducting will have less restriction than flexible duct.

I assume that the air cooled hoods are 6”, meaning any decent inline fan will be around 400-450cfm and cool both of those lights just fine.

Also just remember that sucking air out of the hoods while slightly better at cooling most air cooled hoods are not completely sealed and any smell in the tent will get sucked through those areas and defeat the carbon filters purpose. The only way to change this is to tape/seal up the hood or put the fan before the hoods. Either way will accomplish what you need.
 
bazookajoe

bazookajoe

Well-Known Member
GP Rust said:
Hey guys and thanks for the Replies. Thanks bazooka. Do you think it is fine to do like that? I worry that the exhaustimg will be less efficient - i am kind of worried about heat. The reason i put it after is to have clean uninterrupted sucking :bigjoint:, but I am not an expert amd would love input.

I have changed my opiniom of venting in to the attic as well...after experiencing a warm day I went up there and was not satisfied with its ability to remove heat. So I am planning on running it out through another room / window.

Will it be alright if the exhaust ducting goes for about 5m after the fan? I am unsure of if the distance will result in the air falling back in to the grow room / stagnating in the pipe...yet i somehow doubt this is physically possible :mrgreen: i got that OCD...

Thanks for tips. Here is some more info about my setup:

2x600w hps in 8x4 flower tent
1x630w cmh in 4x4 veg tent
Flower exh havent bought yet, veg exh is a Hit 125, which should exh the tent comfortable every 1 minute.
10000btu / 1100w portable single-duct AC.

Ive got this all in a room comfortably large enough to contain both tents with working space. Roughly 10x10 ft.

I do not plan on introducing co2 yet, because I have not found an economically feasible means where I live. So I cant seal the grow room, and want to duct the portable AC in to both my grow tents via a DIY splitter.
bongsmiliebongsmiliepeace
Click to expand...
its absolutely fine to do it that way. if i had to guess id say 90% of folks that use air cooled hoods in a tent setup run it that way(unless they're running a sealed room with c02). if you have a centrifugal(inline) fan, not the little cheap plastic bladed duct booster fan, the 5m wont be an issue. using the filter the way i described reduces the output of the fan by probably 20-30(ish)% as air is being sucked thru the filter, but eliminating most of the odor none-the-less. if you run your fan full power you should notice the tent sucking inward. Thats the negative pressure at work and unless its imploding your tent, there isnt anything to worry about, using passive intake that is. if possible, use insulated ducting to insure no exhaust air is leaking back into your room and to keep the the exhausted bulb heat from radiating from cheap foil ducting back into your tent.
your 10k btu ac should be enough to cool the tents depending on your geographical location i guess, but ive heard pretty negative things about the efficiency of the single hose portable ac's. i have not used one so i cant confirm nor deny the claims. if you are using the vent screens (i assume they're standard with all tents)that are meant for passive intake you probably wont need the diy splitter, just keep those screens open and your fan should be able to pull the cool air from ac into each tent.

sorry so long winded, hope this helps. maybe someone with portable ac exp can chime in on the efficiency bit.
 

Attachments

G

GP Rust

Member
bazookajoe said:
its absolutely fine to do it that way. if i had to guess id say 90% of folks that use air cooled hoods in a tent setup run it that way(unless they're running a sealed room with c02). if you have a centrifugal(inline) fan, not the little cheap plastic bladed duct booster fan, the 5m wont be an issue. using the filter the way i described reduces the output of the fan by probably 20-30(ish)% as air is being sucked thru the filter, but eliminating most of the odor none-the-less. if you run your fan full power you should notice the tent sucking inward. Thats the negative pressure at work and unless its imploding your tent, there isnt anything to worry about, using passive intake that is. if possible, use insulated ducting to insure no exhaust air is leaking back into your room and to keep the the exhausted bulb heat from radiating from cheap foil ducting back into your tent.
your 10k btu ac should be enough to cool the tents depending on your geographical location i guess, but ive heard pretty negative things about the efficiency of the single hose portable ac's. i have not used one so i cant confirm nor deny the claims. if you are using the vent screens (i assume they're standard with all tents)that are meant for passive intake you probably wont need the diy splitter, just keep those screens open and your fan should be able to pull the cool air from ac into each tent.

sorry so long winded, hope this helps. maybe someone with portable ac exp can chime in on the efficiency bit.
Click to expand...
No problem at all, I appreciate the help. Please don't let me questions bother you.

Why do you actually advocate for the carbon filter to be inside the tent? It seems you say it will just limit the exhaust capabilities of the fan?

I would like to set my hoods up in a way that exhausts the hot air of the hood as quickly as possible, but allows for a slightly slower tent exhaust - but i cant see this being possible unless I run my hoods on a closed circuit and then exhaust my tent with a slower fan.

Also WRT to your comment about the AC, I have to leave my grow room open to allow for CO2 exchange - so I can't waste the cold air. If I can find a economic and reliable co2 method - im down to do a closed circui
Thanks again!
 
G

GP Rust

Member
AKgrower29 said:
I would limit the length of ducting as much as possible and if it is a straight run, rigid ducting will have less restriction than flexible duct.

I assume that the air cooled hoods are 6”, meaning any decent inline fan will be around 400-450cfm and cool both of those lights just fine.

Also just remember that sucking air out of the hoods while slightly better at cooling most air cooled hoods are not completely sealed and any smell in the tent will get sucked through those areas and defeat the carbon filters purpose. The only way to change this is to tape/seal up the hood or put the fan before the hoods. Either way will accomplish what you need.
Click to expand...
Good ol insulation tape? Any tips when doing that - all the way around the edge of the glass?

Thanks
 
A

AKgrower29

Well-Known Member
I use a metal foil tape seems to take removal after heat better, duct tape does not want to come back off.

Yeah all around the glass and anywhere it looks like smell/air could escape.
 
bazookajoe

bazookajoe

Well-Known Member
GP Rust said:
No problem at all, I appreciate the help. Please don't let me questions bother you.

Why do you actually advocate for the carbon filter to be inside the tent? It seems you say it will just limit the exhaust capabilities of the fan?

I would like to set my hoods up in a way that exhausts the hot air of the hood as quickly as possible, but allows for a slightly slower tent exhaust - but i cant see this being possible unless I run my hoods on a closed circuit and then exhaust my tent with a slower fan.

Also WRT to your comment about the AC, I have to leave my grow room open to allow for CO2 exchange - so I can't waste the cold air. If I can find a economic and reliable co2 method - im down to do a closed circui
Thanks again!
Click to expand...
no bother with the ?'s bud.
wether the filter is in or out of the tent, as long as its attached to the fan itll slow the fan down some due to static pressure. im not necessarily advocating the filter in the tent thats just the way ive done mine in the past and will do in the future. ive only seen them outside the tents when more than 1 room is being vented with a single fan and filter or filter is to big or heavy to be hung in the tent. im not saying dont do it your way, by all means, do what works for you.im just suggesting options.
seperate circuits for cooling bulbs and exhaust isnt a bad idea, just requires another fan, idk what cfm your fan is but i assume its atleast a 6" 400+cfm which is more than capable of cooling 2 600w bulbs and exhausting room of smell and heat so other than personal preference, 2 circuits arent needed.
do you not have the passive intake holes toward the bottom of your tent to allow fresh cool air in?
 
Ripped Farmer

Ripped Farmer

Well-Known Member
GP Rust said:
Hi, thanks for the reply.

Do you mean the filter kind of slows down the exhausting of the tent itself...thereby allowing for a more 'continuous' exhaust of the hoods?
Click to expand...



The filter does slow down air flow some. I'd put the filter inside the room, connect to ducting, run into hoods, and then ducting out the last hood through wall, and then more ducting all the way to your attic. This keeps all the stink air from getting into the system without first passing through the filter. You will need an intake port on your tent (fancy name for a hole in the wall) so fresh air can come in and replace the air that the fan/filter is sucking out.

I'd put your fan in the attic and "suck" through all this ducitng and the filter, dont push through, this way you wont have to listen to the fan. Technically you could put the fan anywhere after the filter if you wanted, just so long as it is sucking though the filter and then pushing air through the rest.
 
Ripped Farmer

Ripped Farmer

Well-Known Member
bazookajoe said:
no bother with the ?'s bud.
wether the filter is in or out of the tent, as long as its attached to the fan itll slow the fan down some due to static pressure. im not necessarily advocating the filter in the tent thats just the way ive done mine in the past and will do in the future. ive only seen them outside the tents when more than 1 room is being vented with a single fan and filter or filter is to big or heavy to be hung in the tent. im not saying dont do it your way, by all means, do what works for you.im just suggesting options.
seperate circuits for cooling bulbs and exhaust isnt a bad idea, just requires another fan, idk what cfm your fan is but i assume its atleast a 6" 400+cfm which is more than capable of cooling 2 600w bulbs and exhausting room of smell and heat so other than personal preference, 2 circuits arent needed.
do you not have the passive intake holes toward the bottom of your tent to allow fresh cool air in?
Click to expand...

I advocate filter in tent for this reason...control the stink at the source.

Why would you want to let all that stink air leave the tent only then to try and clean it up in an adjacent space?

If you dont filter in the tent, it will seep out. If you dont filter at all, your attic is gonna stink and so eventually will the rest of your house and outside the home as well.

Stink problems aren't progressive. You come home from work one day and open your car door only to realize that it stinks clear out to the sidewalk. Solve this problem BEFORE its a problem!
 
Last edited:
You must log in or register to reply here.
Top