As an expert in the field of air duct cleaning, I can confidently say that the process is not always necessary. While it may seem like a logical maintenance activity, it may not be as beneficial as it sounds. In fact, studies have shown that cleaning air ducts can actually create more problems than it solves. Companies often advertise health benefits or suggest that cleaning ducts will reduce energy bills by improving system efficiency.
However, there is no data to support these claims. Even if the ducts are dirty, cleaning them probably won't provide any measurable benefit. In fact, the few independent research conducted on duct cleaning indicates that the process accumulates so much dust that it creates a greater problem than it solves. The truth is that the dust that settles in the ventilation system usually stays where it is and is unlikely to reach the air unless it changes. Under most circumstances, dust is inert and harmless, and removing it with cleaning equipment actually creates major problems.
Little research has been done on the effects of duct cleaning. Studies conducted by the governments of the United States and Canada and health professionals who have researched duct cleaning go so far as to recommend its use, but neither do they support it as a routine measure. EPA and CMHC researchers used different methodologies. The CMHC study used several duct cleaning services. The companies were not informed that they were part of a study and the researchers did not control the time spent or the methods used.
The EPA study prescribed and controlled the methods used in a smaller number of homes. While the duct cleaning industry maintains that both studies are flawed, no other research has questioned the findings. And while the equipment and methods used by duct cleaning companies have changed since these studies were conducted, household air ducts haven't. Changing air filters frequently is the best way to keep dust, allergens, and other particles out of the home. With a newly installed system or one in a house you just moved into, check the filter once a month to determine how quickly it gets dirty at different times of the year.
Most should be replaced every two to three months. Although not always part of their basic cleaning services, many duct cleaning companies also tend to clean heating and cooling equipment (heat exchangers, cooling coils, condensate drain pans, fan motors, fan blades and fan housings). While much of the energy used to power heating and cooling equipment is wasted, that waste is due to equipment inefficiency, poor insulation, leaks around doors and windows, and unsealed ductwork. While there are some benefits to cleaning and maintaining heating and air conditioning equipment, these benefits are relatively small and little energy waste is attributed to dirty ducts or equipment. The CMHC researchers found that when duct cleaners also cleaned the fan blades there was a small reduction of particles suspended in the air. Cleaning the fan could also slightly improve the energy efficiency of the system. The same goes for the evaporator coils in your home cooling system.
Evaporator coils cause condensation and dehumidify air before it circulates around the house. Condensed moisture can cause dust and other particles to adhere to the coils and accumulate in them. In addition, by cleaning the collector tray (and draining nozzle) located under the coils it is ensured that dirt does not accumulate and enter into the system. It also prevents water from accumulating in and under the coils which can cause mold problems. Also consider inspecting your duct system for leaks as leaking ducts reduce efficiency and introduce air quality problems.
If any member of your household has specific health problems such as allergies or asthma consult your doctor first. It is important to identify if there is a problem so that your doctor can suggest alternatives to cleaning your air ducts. Start by identifying if your air ducts are part of this problem (they probably aren't) and if cleaning them will help (it probably isn't). If you suspect that you have a mold problem either because of visible growth or because of a musty smell coming out from supply grilles then cleaning your air ducts won't do much good if it doesn't get rid of mold. Mold starts with a moisture problem and usually isn't caused by your air ducts themselves but rather by your cooling system's evaporator coils which your heating and air conditioning contractor can inspect and maintain. Leaky return ducts can also introduce moisture so if you suspect a mold problem consider having a service company inspect your system for leaks. Ordering things only helps to a certain extent if in first place you keep buying too much.
Duct cleaning isn't necessarily a bad idea but truth is that it's not necessary in most cases. In fact cleaning normally dusty air ducts provides no real value. If done properly however duct cleaning can be useful in limited situations. It seems like a logical maintenance activity but cleaning your home's air conditioning system may not be as good an idea as it sounds because clogged and dirty air ducts make your AC work harder shortening its life span. So before you decide on getting your air ducts cleaned consider all these factors first as well as inspecting for leaks around doors windows or unsealed ductwork which can be more beneficial than just getting them cleaned.
