Everyone these days knows what a safety hazard fine dust particles can be to the human respiratory system and so a woodshop exhaust system is the best way to combat this risk. In a woodshop you may also have fumes from various solvents and stains as well. None of these are good for you to breathe in so an exhaust system is needed. You should wear dust masks even if there is a good woodshop exhaust system.
Planning the System
We will assume this is a home wood shop, and a smaller area than a commercial size shop. You will need to plan what kind of exhaust system you need to have in the shop for your needs. Is it going to have to move lots of dust from sanding as well as fumes from paint, solvents and polyurethane paint? The more it has to move, the more the suction and the bigger the exhaust fans and filters are needed (you can’t just suck it all outside, that would be polluting).
Once you have decided what kind of filtration system you are going to use, make a sketch of how and where you want the system to go, so you have a rough guideline. Then it is off to the hardware store for your materials and maybe a video to give you a better idea on how to hang the ducts etc.
The filtration part of the system needs a vacuum set up, and different size filters and several collection points along the way, before the air is exhausted out through vents.
Getting a System
Any good woodworking catalog will stock the parts needed for the do it yourselfer to set up his own filtration system, or you can buy one that is already set up and just hook it into the duct work. What you decide to do is generally a financial decision since these systems can be quite pricey.
Once you have all your components on site, along with your sketch, it is time to start hanging the duct work. For this you can use stainless steel wire and sling the system up with the wire and U-shaped fasteners, or you can screw it right to the ceiling with brackets if you prefer.
All of the dust producing sanding and cutting areas needs to have a suction vent right at the table you are using for a workbench, to collect the dust as it is made. Placing the tables at the perimeter of the room makes this an easier thing to do.
Where to Put the Filtration Unit
Now that the basic duct work and filtration is put in it is time to decide where the filtration unit it self will go. It can be placed outside the workshop in a room of its own if it is big and noisy, that means a bit more duct work.
Once you have the system hooked up and the filters in place, test it out to make sure it works.
You should turn on the system before anyone starts making dust in the room so it has the time to keep the air clean. Even so, for safety you need to wear dust masks. This system should be good for the fumes from the paints and solvents too.
You can do a reasonable job with the materials you can find in the woodworking shops for the home shop. If you are building a shop for commercial use, you will want to have a professional woodshop exhaust system installed.