Air conditioning maintenance and duct cleaning are two distinct procedures that should be completed by a professional. While HVAC maintenance should be done annually, duct cleaning should be done every two years. The Environmental Protection Agency (EPA) has not found any evidence that duct cleaning prevents health problems, but it is still important to keep your air ducts clean. It's important to note that dirty air ducts are just one of many possible sources of particulate matter in homes.
Pollutants from outdoor and indoor activities, such as cooking, cleaning, smoking, or just moving, can cause greater exposure to pollutants than dirty air ducts. In addition, there is no evidence that a small amount of household dust or other particles in air ducts poses any health risk. Before cleaning, reconditioning, or replacing the ducts, the cause or causes must be corrected, or else the problem is likely to reappear. If you decide to have your air ducts cleaned, take the same consumer precautions you would normally take when evaluating the competence and reliability of the service provider.
As long as cleaning is done properly, there is no evidence to suggest that such cleaning is harmful. It may be beneficial to clean components of the heating and cooling system (e.g., coils and fans) to improve system efficiency. You may also want to consider cleaning your air ducts simply because it seems logical that the air ducts will get dirty over time and should be cleaned from time to time. The EPA does not recommend that air ducts be cleaned routinely, but only when necessary.
However, they recommend that if you have a furnace, stove, or fireplace that burns fuel they be inspected for proper functioning and maintained before each heating season to protect against carbon monoxide poisoning. Whether you decide to clean your home's air ducts or not, preventing water and dirt from entering the system is the most effective way to avoid contamination. If you decide to clean your heating and cooling system, it's important to make sure that the service provider agrees to clean all components of the system and is qualified to do so. In addition, the service provider may propose the application of chemical biocides, designed to remove microbiological contaminants, inside ducts and in 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 investigated and you should be fully informed before deciding to allow the use of biocides or chemical treatments in your air ducts. They should only be applied, if at all, after the system has been properly cleaned of all visible dust or debris. Knowledge about the potential benefits and potential problems of air duct cleaning is limited.
Since the conditions in every home are different, it's impossible to generalize about whether cleaning your home's air ducts would be beneficial or not. On the other hand, if family members have unusual or unexplained symptoms or illnesses that you think might be related to your home environment, you should discuss the situation with your doctor. The EPA has published several publications for guidance on how to identify potential indoor air quality problems and ways to prevent or fix them. You might consider cleaning your air ducts simply because it seems logical that they will get dirty over time and should be cleaned from time to time. While there is still debate over regular duct cleaning's value, there is no evidence suggesting such cleaning is harmful when done properly. On the other hand, if a service provider fails to follow proper duct cleaning procedures, it can cause indoor air problems. For example, an inadequate vacuum collection system can release more dust, dirt, and other contaminants than if left 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 to make difficult and expensive repairs or replacements. In addition, some research suggests that cleaning dirty cooling coils, fans, and heat exchangers can improve efficiency of heating and cooling systems. However there is little evidence to indicate that simply cleaning the duct will improve efficiency significantly.