How many CFM do I need?

I have had my filter for a couple of years. I think it might be clogged or maybe I need a larger fan.

My tent is 20"deep 5'tall and 3' feet wide. How many CFM do I need again?

1-3 X your tent's cfm, depends on your light's heat

Koondense said:

1-3 X your tent's cfm, depends on your light's heat

Click to expand...

Hot as hell. one 150w hps and 4 23w CFLs. My current fan is 4"/100MM inline mixed flow duct fan rated at-101 / 97 CFM and it was doing ok until recently. I think my filter may be clogged.

Could be the filter, maybe too high RH in the cab for the filter or just too old.
You need no more than 100cfm for the room, the best would be to buy a 125 cfm fan with rpm control.

Koondense said:

Could be the filter, maybe too high RH in the cab for the filter or just too old.
You need no more than 100cfm for the room, the best would be to buy a 125 cfm fan with rpm control.

Click to expand...

I removed the filter and the temps dropped 10 degrees.

...yeah, can you post some pics of your equipment?

...and 'a couple years' is too long for any carbon scrubber and not because they become 'clogged' and retard air flow but rather because the carbon becomes too filled with odiferous molecules and lose thier effectiveness.

...and here is a thread that will help you understand what the requirements are.

Ventilation 101

...just to make it easy there are some rules of thumb, first, go with a fan bigger than you need and add a speed controller.

...then, the formula for figuring how many CFMs in your space is WxLxH so a 4x4 tent would be 4x4x6=96 cubic feet so in this example you'd want a fan capable of exchanging about 200+CFMs or cubic feet per minute.

...in my own 4x4 Secret Jardin DR120 i use a 6inch fan with a speed controller that allows me to run the fan at about 5/8th's full power which means it runs quieter and with less stress to the fan while also giving me extra power when and if i need it.



peace, bozo