Collect all the dust
There are 3 sizes of "dust":
1. larger pieces called shavings or chips from a jointer or planer.
2. saw dust from a table saw, miter saw etc.
3. fine dust from a sander, some of which will become airborne.
It always best to cellect the "dust" right at it's source whether over the saw blade or off the small dust port on the sander. A 4" line is often used to collect the dust that is thrown by the planer or jointer and on the base of the table saw. Newer table saws have a undertable blade housing that does a far better job of collection the dust than a 4" hole in the bottom of a cabinet saw.
A basement is an enclosed area with a low ceiling. Your joists are exposed and that's a problem since any dust will gather on them and any disturbance will knock it off back into the shop air. I would cover the exposed joists, even if only with Visqueen or cheap 1/4" paneling.
The other issue in basements is that any return air duct works will draw any shop air dust into the heating system and redistribute it through the house unless filtered. It's obvious you are concerned about heat loss in the basement since the window is covered in Visqueen.
If you were to put your air filtration system into the window opening and exhaust the air outside. that air would have to be replaced through another opening somewhere in the house. That's another problem. Any exhaust gases from a hot water heater or furnace or chimney will be drawn back down into the house because of the created negative pressure. It's best to just filter and shop air and return it into the shop if you are concerned about heat loss. If not then exhaust it all outside.
Some folks vent their dust collection outside directly and use nor filter bag or cannister. It's very efficient for dust collection and it may not be a big heat loss depending on the minutes of operation and other factors.
The 3 components I use to collect dust are shop vacs at each machine when possible, 4" piped runs to the main dust collector and an over head air filtration system.
The answer to your question will only be as detailed and specific as the question is detailed and specific. Good questions also include a sketch or a photo that illustrates your issue. (:< D)