I use to have a big cyclone fan (my shop 320m2, fan max 2000m2) that blown out trought the wall to the filter barrel out side. But since we have long and cold winter and I didnt want to blown warm air out I bought one of these:
http://www.nederman.com/products/por...ors/filtercart
Actually I still have the cyclone but dont need to use it. Maybe in a emergency to chance all air in the shop.
It can be next on the job but I connected to existing ducts. I have 6" duct network with close-out on every directions so I can turn the suction heve I need it. Plasmatable, postlift, grinding or frametable.
Now all the heat stays inside and all the dust stays in the filter. Even HEPA filter can be installed but thought that is overkill in the fabshop.
This been thinking to install the curtains like Vince show'd. But I thinked that would put them 3-5ft down from ceiling. My shop inside is 10.5ft high. That way they prevent most of the airborne transfer but dont mess moving stuff like long tubes around the shop.