When air ducts become clogged with dust and dirt, they can reduce energy efficiency, increase health risks due to airborne allergens, and more. The Environmental Protection Agency (EPA) urges you to read this document in its entirety, as it provides important information on the subject. Duct cleaning has never been proven to actually prevent health problems. This is because much of the dirt in the air ducts adheres to the duct surfaces and does not necessarily enter the living space.
It's important to note that dirty air ducts are just one of the many possible sources of particulate matter that are present in homes. Contaminants that enter the home through both outdoor and indoor activities, such as cooking, cleaning, smoking, or simply moving around, can cause greater exposure to contaminants than dirty air ducts. In addition, there is no evidence that a small amount of household dust or other particles in air ducts poses a health risk. If any of the conditions identified above exist, it usually suggests one or more underlying causes. Before ducting is cleaned, modernized, or replaced, the cause or causes must be corrected, or else the problem is likely to recur.
Some research suggests that cleaning the components of heating and cooling systems (e.g., cooling coils, fans, and heat exchangers) can improve the efficiency of heating and cooling systems. However, there is little evidence to indicate that simply cleaning the duct system will increase the efficiency of the system. You can consider cleaning the air ducts simply because it seems logical that they will become dirty over time and need to be cleaned from time to time. As long as the cleaning is done correctly, there is no evidence to suggest that such cleaning is harmful. The EPA does not recommend that air ducts be cleaned routinely, but only when necessary.
However, the EPA recommends that if you have a furnace, stove, or fireplace that burns fuel, it be inspected for proper functioning and maintained before each heating season to protect it against carbon monoxide poisoning.If you decide to clean your air ducts, take the same consumer precautions you would normally take when evaluating the competence and reliability of the service provider. Whether or not you decide to clean your home's air ducts, preventing water and dirt from entering the system is the most effective way to prevent contamination (see How to Prevent Duct Contamination). If you decide to clean your heating and cooling system, it's important to ensure that the service provider is committed to cleaning all components of the system and is qualified to do so. In addition, the service provider can propose the application of chemical biocides, designed to remove microbiological contaminants, to the inside of the ducts and to other components of the system. Some service providers may also suggest applying chemical treatments (sealants or other encapsulants) to encapsulate or cover the inner surfaces of air ducts and equipment housings because they believe they will control mold growth or prevent the release of dirt particles or fibers from the ducts.
These practices have not yet been thoroughly researched and you must be fully informed before deciding to allow the use of biocides or chemical treatments in your air ducts. They should only be applied, if any, after the system has been properly cleaned of all visible dust or dirt. Knowledge about potential benefits and potential problems of cleaning air ducts is limited. Since conditions in every home are different, it's impossible to generalize about whether cleaning air ducts in your home would be beneficial or not. On one hand, if family members have unusual or unexplained symptoms or illnesses that you think could be related to your home environment, you should discuss this with your doctor. The EPA has published several publications as guidance on identifying potential indoor air quality problems and ways to prevent or solve them.
While debate over value of regular duct cleaning continues, there is no evidence to suggest that such cleaning is harmful provided it is done correctly. On other hand, if service provider doesn't follow proper duct cleaning procedures, it can cause problems with indoor air. For example, an inadequate vacuum collection system can release more dust, dirt and other contaminants than if it had left ducts alone. A careless or inadequately trained service provider can damage your ducts or your heating and cooling system which could increase your heating and air conditioning costs or force you make difficult and costly repairs or replacements. You can consider cleaning air ducts simply because it seems logical that they will become dirty over time and need be cleaned from time to time.
If you think that cleaning ducts might be good idea for your home then take same consumer precautions you would normally take when evaluating competence and reliability of service provider.