@DanesRFun As Steve pointed out, it's important to identify the issue that you are trying to rectify. You're in an old, urban basement without access to a garage and the table saw is in the shed. Roger that.
If you're doing sanding in your space (or any kind of particulate generation), you want to contain that as much as possible. This is where Festool excels best. The sanders and extractors are designed with this specifically in mind. If you don't have a sander kit then get yourself both the ETS EC 150/5 and CT MIDI I.
Next, you'll want to consider larger dust collection. To note: when people refer to dust extraction, it's typically for fine dust and lower volume tools, like sanders. When they say dust collection, it's typically for higher volume and larger chips, like from thickness planers and jointers.
The market is filled with all sorts of dust collectors which is why it's important to identify your requirements. The main point of all this is to keep your workshop clean and your lungs free from contaminants. The simplest way is to exhaust it out of the space. If you visit large workshops, this is essentially what they do. They blow everything outside the building - typically to very large cyclones that contain the sawdust in suspended bins that the business can back a box trailer under, dump the sawdust in and haul it away. In those circumstances, they're not worried about filtration.
At my friends workshop in the woods, we're planning an dust collection setup that does not include filtration. It's going to be fairly simple: Old, 3hp Delta motor with fan assembly he got off marketplace and an old 55ga drum I had lying around. We're gonna mount that outside the workshop, cut a hole through the wall for the hose and let 'er rip. Because it's blowing outside, no need for a filter.
The cyclone is a conical shaped apparatus that is designed to separate most of the airborne particulates and contain them. Depending on your setup, it won't be 100% effective but they work very well. Why you see HEPA filters is because a lot of these are setup inside the workspace due to necessity - and it is the HEPA filters that remove the finest and nearly invisible particulates that your nose hairs won't filter out and that will give you lung cancer and cause rapid death. Ideally, we want to avoid that.
So that's dust extraction and dust collection. The third leg is dust filtration in the workspace and I like the idea of whole room and near-field filtration. Festool recently made this easy with the release of their SYS-AIR models that are systainer sized (so relatively compact) and can be placed next to the workpiece. I myself am a bit cheap so I fashioned a near-field filter by attaching a 4" Merv 11 filter to a 20" box fan and then a 1" Merv 7 filter on top to act as a pre-filter for the Merv 11.
Flying above the room is a Corsi-Rosenthal Type box that I made with another 20" box fan and five 1" Merv 13 air filters. This filters the smallest of particulates that they say are light enough to be suspended airborne for up to 72 hours. Like you, my consideration for the lungs in paramount so I wanted to do everything I could.
In my garage, I also open the doors as much as possible. In your case, I'd also be looking to add an exhaust fan in addition to all these to blow additional air out. And I would also be looking for the best way to bring fresh air into the space. Because you always want fresh air circulating in your space.
These are the main pillars: Extraction, Collection, Filtration and Exhaust. I spent the money on the Festool Extractor and have built everything else. I mostly have small benchtop type tools, so most of the collection can be handled well by a big shop vac but I'm also building a dust collector. Spent the past few weeks assembling the parts: Central Machinery collector blower on clearance at Harbor Freight, Oneida Super Dust Deputy with bin, and a very large canister air filter - both on Marketplace. Now it's time to fashion a rolling rig to make it all work.
Enjoy the process!
