What kind of duct is this. It seems to be some kind of owens corning insulation board. Is is dangerous for air to travel threw and breath? I have recently moved into a rental where this product is installed. I have ran the AC for almost 2 months. I have aquired severe breathing problems during this time. I finally went to hospital. They confirmed I have emphysema. Ive had no health issues in the past. Im 38. Fibreglass? ??