Your question: Does a humidifier help with chronic bronchitis, emphysema, or pneumonia?
My answer: I would not recommend a humidifier for any person who has a lung disorder, especially if you have asthma, chronic bronchitis, emphysema, cystic fibrosis, or any similar disorder. Why? To learn more you can check out this post.
Note: the post is written for asthmatics, but the information also applies for the other diseases mentioned.