Dealing With Fiberglass Insulation

In the air handlers, plenums and ductwork of the HVAC systems they vacuum, often industrial air duct cleaning contractors find fiberglass insulation. Engineers originally developed to insulate fiberglass in HVAC systems for acoustic or thermal purposes (help monitor sound) (to help prevent temperature loss). It can be a great struggle to work with fiberglass insulation. It can be degraded or damaged by:

  • Air erosion from the air handler’s ventilator
  • Contaminating smoke from a fire
  • The presence of excessive moisture and a microbial food supply causes mold or microbial contamination (dirt).
  • What’re you doing? What choices are yours?

The first thing you have to do in these situations is to test the fiberglass to assess the shape it is in. Will it survive the rigors of washing, or when you hit it, will it fall apart? Are they wet? Click here learn about them.

You have the following options to consider in air handles and wide plenums/ductwork, where you can crawl:

You can vacuum the insulation or clean and powder the insulation if the fiberglass insulation is in decent condition and can resist the rigor of washing.


You should strip the insulation or remove and coat the sheet metal or remove and cover it with new insulation or remove and replace it with new coating material or remove and replace it with closed cell material if the fiberglass insulation is not in good condition and cannot hold up to the rigor of washing.
If the insulation is damp, the insulation can be removed, or the sheet metal can be removed and covered, or the new insulation can be removed and replaced, or the new coated insulation can be removed and replaced, or the close-cell material can be removed and replaced.