I learned something that I wanted to share with this group. It concerns fans and filters. Currently I am growing in a 5' x 5' Gorilla Grow Tent. I have been cooling it with a 6” AC Infinity basic fan. As I am going to start using my 3' x 3' Gorilla Grow Tent for flowering again so I decided to move this fan and filter to my smaller tent and upgrade the fan inside of my larger tent with the AC Infinity Cloudline T8 (8") with Temperature and Humidity Controller. While looking around their site I stumble on a page entitled Grow Space Ventilation 101: https://www.acinfinity.com/pages/tec...ing-guide.html. It discussed how add-ons to one’s fan can impact performance. Simply put after calculating your tent size you need to account for ducting, filters and lights.
For example, a 4’x3’x6’ grow tent has a baseline CFM of 72. Multiply this figure by the efficiency percentage of each component. If you add a carbon filter (60%), ducting (~20%), and a silencer (20%) to your ventilation system, you get 166 CFM. From here, factoring in your grow light’s heat output (≤50%) will give you a required CFM of 249.
Multiplying your base CFM (72) by the ducting (20%), carbon filter (60%), silencer (20%), and grow light heat (50%) of your choice will yield about a required 249 CFM.
(Base CFM x Component factors) x (Grow light heat) = Required CFM
In this example:
(72 cubic feet / 1 minute) x 1.2 x 1.6 x 1.2 x 1.5 ≈ 249 CFM. In other words you need a fan that will move at least 249 cubic feet per minute. Most of you probably aren’t running silencers so you can pull the 1.2 from the example.
In this example your filter needs to be able to handle at least 249 cubic feet per minute or you are going to shorten the life of your inline fan.
Here is one last point. I would tend to oversize the fan and possibly the filter. Think of it this way. If you have to run your fan at full capacity in your grow tent or room because of these factors you are going to shorten its’ life the same way you would any machine that was required to run at its’ maximum capacity for extended periods of time. In my case the room where my tent is located is upstairs on the southwest corner of my house which is the hottest part of the house. When warm weather comes I would have to run a smaller inline fan at pretty much its’ maximum capacity to keep my girls cool.
To determine your CFM multiple your tent’s length x width x hight. Your fan needs to exchange all of the air in the tent every minute.
If you use ducting multiply the above by 1.2.
If you use a carbon filter multiply the above by 1.6.
If you use a silencer multiply the above by 1.2.
For your lights multiply the above by at least 1.5.
For my 5' x 5' Gorilla Grow Tent I need a filter that can handle 504 cfm. So I am going to end up getting AC Infinity’s 8” inline fan which moves 740 cfm of air. This will allow the fan to handle this load at 46% of its’ capacity and should also be sufficient if I add another light to the tent.
For example, a 4’x3’x6’ grow tent has a baseline CFM of 72. Multiply this figure by the efficiency percentage of each component. If you add a carbon filter (60%), ducting (~20%), and a silencer (20%) to your ventilation system, you get 166 CFM. From here, factoring in your grow light’s heat output (≤50%) will give you a required CFM of 249.
Multiplying your base CFM (72) by the ducting (20%), carbon filter (60%), silencer (20%), and grow light heat (50%) of your choice will yield about a required 249 CFM.
(Base CFM x Component factors) x (Grow light heat) = Required CFM
In this example:
(72 cubic feet / 1 minute) x 1.2 x 1.6 x 1.2 x 1.5 ≈ 249 CFM. In other words you need a fan that will move at least 249 cubic feet per minute. Most of you probably aren’t running silencers so you can pull the 1.2 from the example.
In this example your filter needs to be able to handle at least 249 cubic feet per minute or you are going to shorten the life of your inline fan.
Here is one last point. I would tend to oversize the fan and possibly the filter. Think of it this way. If you have to run your fan at full capacity in your grow tent or room because of these factors you are going to shorten its’ life the same way you would any machine that was required to run at its’ maximum capacity for extended periods of time. In my case the room where my tent is located is upstairs on the southwest corner of my house which is the hottest part of the house. When warm weather comes I would have to run a smaller inline fan at pretty much its’ maximum capacity to keep my girls cool.
To determine your CFM multiple your tent’s length x width x hight. Your fan needs to exchange all of the air in the tent every minute.
If you use ducting multiply the above by 1.2.
If you use a carbon filter multiply the above by 1.6.
If you use a silencer multiply the above by 1.2.
For your lights multiply the above by at least 1.5.
For my 5' x 5' Gorilla Grow Tent I need a filter that can handle 504 cfm. So I am going to end up getting AC Infinity’s 8” inline fan which moves 740 cfm of air. This will allow the fan to handle this load at 46% of its’ capacity and should also be sufficient if I add another light to the tent.
