- By empiredd
In most cases, no. If the problem is low airflow or spreading dust, simply cleaning out the duct will almost always be sufficient. If you have mold, however, it depends on the type of duct—fiberboard ductwork will probably need to be replaced to eliminate the infestation, while metal ducts can just be cleaned. If you have minor leaks in your ductwork, then minor repairs should so the trick. For major problems, however, you might need to replace the duct. You’ll also need to replace your ductwork if you’re replacing your air conditioner or furnace, in order to ensure that the ducts are a good match. If the ducts don’t meet the necessary specifications of a heating or AC unit, then the warm or cool air can’t get to you, which defeats the purpose.