Overview (3) Heidi Klum was born in Bergisch Gladbach, a small city near Cologne, Germany, in 1973. Her career as a top fashion model and swimsuit star began almost by accident when, on a lark, she submitted photos to a model competition hosted by Petra, a young woman's magazine.
The National Air Duct Cleaners Association recommends getting your air ducts cleaned every three to five years. Ed Mack, owner of Air Duct Professionals in Lake Elsinore, California, says homeowners should consider doing it every two to five years, depending on their circumstances.
1 While there's no harm in having your ducts cleaned even if you don't have any of those four factors (other than the $400-$1000 expense),  provided that it is done properly [emphasis theirs] .