Our metal ductwork, installed in 99, has a black installation type material inside the metal work. Some of the main area going into the fan area is made completely with this material. Is this material a source of dust and dirt?


It can be yes. That's an acoustic lining or ductboard which I'm not a huge fan of but that's my personal opinion. It's widely used.

Updated on January 8, 2018

Original Article:

How to Maintain & Clean Your Air Conditioner Yourself
By Dan Robbins