This topic is not directly related to audio so I thought that probably the "Machine shop" is the right section but please feel free to move it if necessary

I need to make a fume extraction system since I do quite a bit of soldering and I think I've inhaled enough fumes for 2-3 lifetimes...
I have already drilled a hole in my workshop's wall that is directly connected to a chimney so all the fumes will be extracted outdoors instead of using filters. The idea is to use a 12VDC inline fan connected to one of these PWM controllers you can find online that are used for DC motors and LEDs.
I think I'll get one of the following fans. I just haven't decided yet on how many CFM I would need.
http://www.seaflo.com/en-us/product/list/321.html Obviously these are 2-wire DC fans.
I'm wondering if someone has attempted something similar and if so I would really appreciate some advice!
The main questions that arise from such a project are:
a) How many CFM would be appropriate?
b) Will these 2-wire fans work with a PWM controller and if so what would be a good PWM frequency? I have found some 3kHz and some 20kHz PWM controllers
c) Are there any other issues that I should consider by doing such a project? FWIW, I'll most likely be using loc-line 2.5" vacuum system. Either the
simple one or the
anti-static one.
As I already said, any advice would be much appreciated!
