my intake exhauts fan : 16cm, cooltube :15 cm ,trouble ?

[asparagas]

hello
i will buy a vortex model extract fan 16 cm.but i have a cooltube that it is 15 cm diameter.i have a carbon filter that its diameter is 15cm

but exhauts fan is 16 cm.is it a problem ?

should i change my fan ?

how can i connect them each other ?

and one question more,if exhauts fan were 20 cm and cooltube were 15 cm,it would be a problem ?

air goes> carbon filter>cooltube>fan>outside of box

 

[ArtVandolay]

IMHO, this is rounding error, safe to ignore. I (THG, too, I think) have 3 inch cool tubes hooked up to 4 inch ducting

 

[asparagas]

thanks dude