Big enough exhuast fan???

You can calculate air exchange rates based on volume all you like but it doesn't help for heat removal since you don't know the OPs ambient air temp and how many degrees above that he can afford to rise.

Dividedsky said:

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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coreywebster said:

You can calculate air exchange rates based on volume all you like but it doesn't help for heat removal since you don't know the OPs ambient air temp and how many degrees above that he can afford to rise.

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True, true. Mine was just a rough estimate. I'd get a much higher rated cfm myself. It was just to get you in the ballpark.

Funny I saw this post though, think im going to snag a new 8" fan today. Going to go with vortex, if they have it at the local hydro shop...and if it doesn't cost an arm and a leg.

The cfm ratings are baced in open flow.
I wonder how they rate hooked to a carbon filter?

Bookush34 said:

The cfm ratings are baced in open flow.
I wonder how they rate hooked to a carbon filter?

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i just saw a couple things online that said to add 20% cfm for the carbon filter.

Bookush34 said:

1 6” fan per two lights. Drawing from out side the tent. Then a 8” fan and filter in the tent is what you are gonna need IMO

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im leaning more towards this idea, i found a 10" carbon filter (1150cfm) and i could use the vortex 10" fan (780cfm) for the room cooling/smell extracting and then two 6" fans (256cfm ea.)for the lights and cool the lights seperately from the exhaust fan. That would give me about 1300cfm total. I can pick up what i need for ~$300.

More is better. Can always turn them down. I have a 6” and 4” for my 3x3 tent. With leds. Heat is never a issue. Well maybe lack of it sometimes

Since your'e building your grow room maybe you can install one of these in the walls.
https://agron.io/products/hurricane-pro-shutter-exhaust-fans?variant=12281731317852&gclid=CjwKCAjwstfkBRBoEiwADTmnECUJGG8bzrHKMbxaLC9gnt83HIyllN_K3RwwyDdj5g5RwT2CmjcFNxoCkcUQAvD_BwE

BostonBuds said:

Since your'e building your grow room maybe you can install one of these in the walls.
https://agron.io/products/hurricane-pro-shutter-exhaust-fans?variant=12281731317852&gclid=CjwKCAjwstfkBRBoEiwADTmnECUJGG8bzrHKMbxaLC9gnt83HIyllN_K3RwwyDdj5g5RwT2CmjcFNxoCkcUQAvD_BwE

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i saw those and those would probably work great for cooling but how would i hook that up to my carbon filter or lights? I would probably have to build some sort of baffle with ducting attached. I could see that causing some extra restrictions,and how powerful the suction on those things is what im not too sure of.

ok guys this is kind of a crude drawing but its my schematic for the 8x8 setup. Ill put the intake vents all around the bottom of the room and the carbon filter right in the middle of the room on the top, and two fans cooling the 4 lights.

That outta work good as long as the room it's in stays cool.

Should probably run the light cooling duct out of the room.

That’s how I do it and the heat goes into the house to help heat in the winter.

Wheb I grew with hps my exhaust temp into the house was 87F.

I duct out a exterior wall in the summer.

kushdaddy1980 said:

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?

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Unless you use insulated ducting a lot of the heat is going to bleed back into the area. Linking 4 lights on 6 inch ducting is a bad idea imo.

growingforfun said:

Unless you use insulated ducting a lot of the heat is going to bleed back into the area. Linking 4 lights on 6 inch ducting is a bad idea imo.

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Well he's appears to have them in pairs with two fans.

Renfro said:

Well he's appears to have them in pairs with two fans.

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The idea changed as the thread went apparently. I didn't read ever comment. Still, 6 inch ducting is not recommended imo and I'd get insulated ducting if he already has the hoods

no i dont have the hoods yet, but your saying the heat will come through the ducting? i know those 1000w lights theyre going to produce a lot of heat. Maybe i will get some insulated if its not too expensive.

Times 2 is correct I think also. I have a 5x5x7.5 tent, and my AC Infinity 6" fan is sized for 2x the cubic feet of my room. Even then, I sometimes have trouble regulating temps to below 78 if it's warm outside.

AlaskaRob said:

Times 2 is correct I think also. I have a 5x5x7.5 tent, and my AC Infinity 6" fan is sized for 2x the cubic feet of my room. Even then, I sometimes have trouble regulating temps to below 78 if it's warm outside.

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Im using a 6" fan in my 2x5x5 closet grow and i have trouble keeping temps down in there too, i also have 3 led lights crammed in there as well. Similar to what im planning on doing with the 8x8. cramming a whopping 4000w into that small space.

kushdaddy1980 said:

no i dont have the hoods yet, but your saying the heat will come through the ducting? i know those 1000w lights theyre going to produce a lot of heat. Maybe i will get some insulated if its not too expensive.

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If you havent bought the hoods yet then absolutely get 8 inch ducted hoods. 8 inch is for 1kw, 6 inch is for under 1kw.

Insulated ducting helps a lot but isnt a must if your moving plenty of air. Ducting is thin foil, heat is easily lost out of it..

Since my digital controller for my fan can control two fans, I'm seriously considering adding another fan to my 5x5. I know the majority of my temp problem is from the ambient temps in the place I have the tent in tho. Right now it's almost 6am, sun is down, lights are off for the past 3 hours, but temp at canopy level is at 73°. Wish I could change the lighting schedule to run overnight but worried about stressing the plants that way when so close to 12/12 flip. I'll definitely be doing night time 12 on. Hard to manage with alaska summer coming and sun is up from 4am to midnight tho.