FAN in duct air

Marco Antonio 123

Commendable
Mar 16, 2016
7
0
1,510
Hi guys!
Maybe a stupid question, but do I install a 80mm fan in the duct air like showed in the picture or I remove the duct air and place only the fan?
Of course fan blowing air from outside to inside .. Lol..
Wio0k0.jpg

Thanks!

Marco