In some cases the duct mains are inaccessible meaning attaching the vacuum isn’t possible. In those situations we use a pull technique with a reverse skipper ball and our clear dust box. This box has a smaller vacuum attached which pulls all airborne particles in, and anything large will scatter around the vent which can be cleaned up once the pulling process is complete.

In this situation the home had a down flow furnace where the supply main ran under the house in a tight crawl space. There was a single oversized return grill that drew air from the hallway.