I have a 1 hp jet brand. I didnt like the bag so I made it just blow out into the alley. Its mounted to the wall up high and has 4" pvc in the attic. I dont use sparks in it at all. I really like the fact that it takes wood, horn, antler and dangerous synthetic handle materials and blows them out back. For hot sparks I let them go into my water/coolant bucket.