An umbilical unit is a pretty good way to have clean air in a small shop. Look for supplied air systems.
One I can recommend is the Breath-Cool supplied air system. Price is very reasonable. It comes with a gas-mask type hood, but you can adapt it to a PAPR respirator helmet like most of us use. You can use it with a Speed-Gas welders hood, a PAPR helmet, or a full paint booth shroud hood, or a meth lab full pharmaceutical suit.
Place the blower and filters in a clean area and run the hose into the dirty shop. Wire a switch from the shop to a socket that the unit plugs into. The hoses are a bit stiff, but you can add a 10-foot section of lighter PAPR type hose at the end you hook up to. This unit is a bit noisy in your hood because of the blowers, but that is something you can get used to or modify.
One simple modification is to get rid of those long stiff hoses and plumb the whole manifold to the shop in 2" PVC pipe. Have it come out in the shop ceiling where the bench is and reduce the manifold pipe to 1.25" (or whatever size your hood's flex-hose will fit on) and put a gate valve on the air outlet so you can shut it off when not using it. Connect a 10-foot light weight and flexible PAPR hose from the air manifold to you hood. You can put a Tee in the manifold and plug in two umbilical hoses if you regularly have another person in the shop.
