Choosing the right sized inline fan, exhaust fan and carbon filter: Please help

[Louiebee123]

Hey guys I need help choosing the right sized inline fan, exhaust fan and carbon filter size

I'm in Australia and we use the metric system, I apologise in advance

My tent is
2.4 metres long
2 metres tall
1.2 metres deep

What would be the best sized
inline fan to bring in fresh air
Exhaust fan and carbon filter
4 inch
6 inch
8 inch
???????
Please help me

 

[Phytoplankton]

I’d go 6 or 8 inch. Might even go 6 inch intake 8 inch for the carbon filter/exhaust fan. You could also get 2 of the same size and put rheostats on them so you can adjust the speeds to get optimum/even in and out flow. The carbon filter will slow the exhaust process a little.

 

[drift]

8" moves more air if you have a hot tent go larger and adjust the speed as needed.

 

[Bill284]

Hey guys I need help choosing the right sized inline fan, exhaust fan and carbon filter size

I'm in Australia and we use the metric system, I apologise in advance

My tent is
2.4 metres long
2 metres tall
1.2 metres deep

What would be the best sized
inline fan to bring in fresh air
Exhaust fan and carbon filter
4 inch
6 inch
8 inch
???????
Please help me

Hello @Louiebee123 hope things are good in Australia.
I ran a 4'x8' flower tent with a 6" fan and carbon filter.
3 vs 900w lights without any heat or smell issues.
If your tent is going to get above 90°f run an 8" but if you never get that hot you will be fine with 6" no problem.
As long as your not running two HPS 1000w lights.
It's exactly what you need.
I also had a 4" blowing fresh air into the tent aswell.
It draws so much the vents won't keep up.
Get a adjustable speed fan for convenience, so you can get better control.
Make sure you keep the carbon filter covered and clean the cover after each grow.
Can't wait to see your grow my friend.
Stay safe
Bill

 

[013]

I don’t run extraction fan / carbon filter setup but when he says keep the filter covered…. I think @Bill284 means…. use a breathe-able lightweight fabric covering to capture fine dust but definitely not a heavy cloth or plastic covering that will restrict air flow

can we get a ruling on that from the judges??? Thanks Bill

 

[Regrowth]

I veg with the side of the tent open and no extraction fan at all. Then I run a small booster fan during flowering. It works fine for me but smell isn't an issue. When smell is an issue you want to create a vacuum effect to make sure smell doesn't escape the tent and will need something larger. Here's a link I found helpful for determining CFM requirements.

 

[Moony]

Dunno if being Australia is going to be an issue. I know you guys get some serious heat lol.

I'd certainly go 8 inch for both. That's a bit overkill. But having more means you have maneuverability incase of extreme temps.

Also you may need to deal with humidity. Make sure your intake and out are at separate ends of the tent so ensure maximum airflow and CO2 for all the plants.

If your struggling with any heat issues and need to take air from indoors and use air-conditioning you could make it so you can bring the intake point to indoors. But having the filter pumping the heat is the main thing I feel.

 

[Bill284]

I don’t run extraction fan / carbon filter setup but when he says keep the filter covered…. I think @Bill284 means…. use a breathe-able lightweight fabric covering to capture fine dust but definitely not a heavy cloth or plastic covering that will restrict air flow

can we get a ruling on that from the judges??? Thanks Bill

Home Run.hehe Thanks.
I assume wrongly most of the time people understand what I'm talking about.
Carbon filters are fine micron usually.
Plug up with dust easily.

Stay safe
Bill

 

[013]

Home Run.hehe Thanks.
I assume wrongly most of the time people understand what I'm talking about.
Carbon filters are fine micron usually.
Plug up with dust easily.

Stay safe
Bill

The main thing is…. we’ve got each other’s backs here!

 

[Skunksta]

I like to have the fliter outside the tent . (in my loft with the fans)
Holes in spare room roof for ducting extreme i know but deals with my smell isses.
Put a dust plate on the intake inside your tent.
No issues with dust BUT do get a much stronger smell of carbon.
I just cut up the cover that comes with the flitter for my dust cover.
Blows out the flitter instead of sucking seems to work better.
PS. 8inch with a controller my vote.

 

[Louiebee123]

Thanks a lot for the feedback. I bought a 6" inline fan plus the same size extractor fan and carbon filter. The place I bought the carbon filter for my other tent and it came with a cloth type material to keep it from getting dust and all other stuff that could be floating about. I have 3 tents and they're rather large. At first I bought cheap l.e.d lights for the vegetative stage but I just bought 2 600w hps light for my 1st tent and I'll be fitting my other 2 tents with the same lights.

I have one last tent to order the extractor fan, inline fan and carbon filter. Then I'll be set.

Today I put in another 8 plants in the last 2 tents and spent 5.5 hours setting everything up.
Can't wait to see my progress as I can only go to my spot once a week. Everything's automatic but I've ran into problems here and there. I'm a beginner and this is my first crop. I'll upload some pictures next Sunday and start a little picture journel

Always happy to get some information so if there's anything I should know im happy to hear from you guys

 

[stinker]

I run a much larger fan than needed and am able to run at low speeds. It is quieter and probably lengthens the life of the fan.

 

[BarryBudz]

Hi, Louiebee123 you dont need to replace the air in your growspace once every minute. thats a really common misconception (probably propagated by vendors, as well as ofc people who dont know any better. the air ventilation has very specific purposes; 1 it prevents molding (which, if you live in a dry environment, is not going to happen), and to provide the plants with co2. co2 ppm indoors usually ranges from ~400-1000; ppm lower than 340 can negatively affect a plants growth; the amount of oxygen produced by the plants will barely change the co2 saturation and as long as your growing space doesnt get too moist; co2 levels should not become an issue if your ventilation can provide a full air exchange more! than once every 5 minutes (not once every 1 minute). additionally; 4 inch ducts (most common ones are not designed for an airflow that surpasses 50cfm anyways (also 4'' silencers have less than 2'' inch radius on the inside; which is why they affect airflow so much), meaning that the stronger your fan is, the less efficient it will work. in summary; if you got something regular, say, a 3x3x6 growing tent (54 cubic feet volume), you dont need any top end fan; it will not do much except be noisy (most grow shops sell fans that provide an airflow of 140 cfm and up) and have their efficiency dampened by running through unfit ducting, while your plants do not need more than 50 cfm.