US Patent 8011359 Auxiliary smoke arresting unit

Smoke escaping from an outdoor wood burning furnace may be effectively arrested with a smoke arresting unit. By mounting a smoke gathering manifold above the furnace door operatively connected to a vacuum source for drawing smoke discharging from the furnace chamber through an open furnace door, the gathered and arrested smoke may be discharged through a separate discharging chimney. The vacuum source may be activated when the furnace fan is switched off and the furnace door is opened for refueling.