The rales could be a residual of pneumonia and of no consequence. Your lack of symptoms is a very good sign. This is evidence against
congestiveHeart failure
Left-sided heart failure
Right-sided heart failure heart failure (CHF) being a problem. The presence of rales without other typical findings is not enough to say that you have congestive heart failure.
For starters, you should have a chest x-ray to check your heart size. If the heart was not enlarged on your recent CT scan, that would suffice. If congestive heart failure remains a concern, you should have an electrocardiogram (EKG) and an echocardiogram. The echocardiogram will tell for sure if congestive heart failure is the problem.
Finally, you should ask for your pulmonologist's opinion about the cause of the rales. Also ask about the appearance of that portion of lung on the last lung CT scan. It is uncommon for an otherwise healthy adult to have documented recurrent pneumonia. If the pneumonia was in the same portion of lung each time that raises the question of a structural problem or a foreign body in that portion of lung. If recurrent, but not in the same location, that raises other questions about your immune status or aspiration pneumonia. You should talk about this with your pulmonologist. Ask specifically if the rales could be a sign of pulmonary fibrosis.