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Big enough exhuast fan???

kushdaddy1980

kushdaddy1980

Well-Known Member
im building an 8x8x8 grow tent out of 2x2's and 2 sided black and white plastic. Im buying 4 1000w hps lights with air cooled hoods. I plan on connecting all 4 lights tgether with 6" ducting and a 550cfm carbon filter at the end with passive intake vents.I found a 440cfm exhaust fan for 60 bucks (vivosun6"). Do you guys think that would be enough to cool the lights down and provide enough airflow for that small area? I know the filter and the 4 lights will cause some restriction. But a cfm calculator online said i only need 171cfm for that size room but what do you guys think?
 
Renfro

Renfro

Well-Known Member
Thats a lot of tent / light for that much blower. If cooling the room with exhaust you wanna exchange the volume of the room 2.5x - 3x a minute. So something like 1500 CFM is what you probably need. Of course ambient temps have a lot to do with it, but I don't see 440 CFM keeping that area cool unless the ambient is cold.
 
kushdaddy1980

kushdaddy1980

Well-Known Member
Renfro said:
Thats a lot of tent / light for that much blower. If cooling the room with exhaust you wanna exchange the volume of the room 2.5x - 3x a minute. So something like 1500 CFM is what you probably need. Of course ambient temps have a lot to do with it, but I don't see 440 CFM keeping that area cool unless the ambient is cold.
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yea its sounding like 440 is not going to be enough
 
kushdaddy1980

kushdaddy1980

Well-Known Member
Renfro said:
These guys have a hella good deal on 10" vortex blowers:
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so the 10" vortex has a 780cfm rating, what if i use a splitter like this,Screenshot_2019-03-23-01-15-03-1.png and hook two lights to each side with a carbon filter at each end. For 114 bucks those are a steal!
 
Renfro

Renfro

Well-Known Member
kushdaddy1980 said:
so the 10" vortex has a 780cfm rating, what if i use a splitter like this
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You could do that, still not sure that one will be enough CFM. It's gonna depend on the ambient temps. Do you have an AC in the room your tent is in? That exhausted heat is gonna warm the room and then cooling will be very difficult even with enough CFM.
 
kushdaddy1980

kushdaddy1980

Well-Known Member
Renfro said:
You could do that, still not sure that one will be enough CFM. It's gonna depend on the ambient temps. Do you have an AC in the room your tent is in? That exhausted heat is gonna warm the room and then cooling will be very difficult even with enough CFM.
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the room outside the tent will be cooled with A/C and i can direct cold air into the intake vents if needed, then ill exhaust the hot air out of the room. Im also wondering if i should set the filters at the top of the room or down closer to the floor, ive seen them installed both ways. I definitly want to pull heat out quickly so maybe i should put them closer to the ceiling.
 
Renfro

Renfro

Well-Known Member
Thats a good deal and the proper CFM. Not sure how long it will last, not familiar with that brand. I do know the vortex blowers are top quality, I have some that have been running non stop for over 6 years lol.

As far as AC goes, for those 4 lights you are gonna want a 1.5 ton (18000 BTU/hr).
 
kushdaddy1980

kushdaddy1980

Well-Known Member
Renfro said:
Thats a good deal and the proper CFM. Not sure how long it will last, not familiar with that brand. I do know the vortex blowers are top quality, I have some that have been running non stop for over 6 years lol.

As far as AC goes, for those 4 lights you are gonna want a 1.5 ton (18000 BTU/hr).
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upon further investigation, read the reviews on this brand and its a mixed bag. Some say they were good but a lot said bearings went bad and they got noisy and one even said it almost caught fire :/ also, i can get that vortex fan for $119 out the door! im probably going to do that.Screenshot_2019-03-23-02-29-20-1.png
 
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coreywebster

coreywebster

Well-Known Member
I wonder what almost catching fire looks like?
Don't buy anything with questionable bearings.

Buy 4 hoods like this.

With a hybrid cool tube/hood like this you don't get much resistance and you can push the hot air through, sucking through the filter and pushing over two lights.
Buy two fans. Have two lines of filter fan , you can connect back into a Y splitter at the end where the heat is taken out the house.
Buy something like a double 8" -12" Y piece.
The cfm requirements you quoted early are only for air exchange purposes to keep co2 in range, not for heat removal.

The above hood has various advantages. Its better sealed, offers less resistance, offers the option to pull or push air though, pushing through can prolong the life of the fan. It also offers a good light spread compared to most cool tubes which have shit spread.
 
Dividedsky

Dividedsky

Well-Known Member
Thought it's length times width times height divided by 2. To see cubic ft of air exhausted every 2 mins..this is a minimum also
 
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