Filters question

[rehabilitatora420]

heya i got a question i want to get a filter and i came in this

filter cotton wool but it came in 3 shapes with

FV 315-400 /​

FV 100-160​

FV 200-250 i think this FV is term for full vacumm not sure but with 400 CFM on each fan inline and exhaust witch one should i get ?
im sry for the lame question but i could not find anything for that ;(​

 

[Roy Growin]

Cotton wool?

 

[rehabilitatora420]

Cotton wool?

its something like this i want to cover the vent holes so i dont drag small bugs because my exhaust and intake fans are taking fresh air from outside and exhausting outside aswell

 

[Roy Growin]

That makes sense
I'm using covid masks as filters on air purifier and dehumidifier