A serious concern

A serious concern in Florida is that the dirt that gets into air conditioning ducts often becomes caked and will be difficult to remove by cleaning methods currently available. When an air conditioner is operating, the air in the ducts is cool and saturated with moisture. Dirt particles exposed to this humid air take up moisture and can stick together and to surfaces in the ducts. Fiberglass lining in ducts make cleaning virtually impossible. The following comments were made at the Symposium, 1990 Indoor Air Quality in Homes: Synthesizing the Issues and Educating Consumers." In answering the question Can you minimize problems from furnace ducts by cleaning them?, Dr. Thad Godish2 replied: "A lot of fiberglass ducts are used, and in high humidity environments, they are going to trap organic dust which can result in mold and bacteria growing on them. In response to that, a number of companies are selling service which really is not going to do much good simply because the ducts get recontaminated so quickly. It is not possible for the cleaning to be as effective as it needs to be. One of the problems with fiberglass ducts is that they have a very rough surface which makes an excellent trap for dust. A lot of dust is organic dust, and if you have organic dust you are going to get the growth of mold and bacteria."