Does Air Duct Cleaning Make Sense for Your Home?


Is there mold growing on your air ducts? Do you smell mold when you turn on the furnace? Do you suffer from asthma or allergies and find yourself having a difficult time breathing in your house? Do you have many pets with lots of fur and dander flying around? Before going for an air duct cleaning, you’ll have cleaned your house and consulted with your doctor for any health issues. It may be time to consider an air duct cleaning. Air duct cleaning cleans your heating and/or cooling system—from the coils to the ductwork that runs throughout your home to the registers and grilles that send air to and from the heating or cooling mechanism. A proper air duct cleaning comprises the entire system. No doubt your home has been bombarded with coupons. No matter where you are looking, you want to be sure you are getting a complete cleaning from a qualified company. Use the information below to help you decide on the best air duct cleaning company for you.


Considering Offers for Air Duct Cleaning 

As you work on improving your house, you may be wondering what an air duct cleaning will achieve. You’ve heard about concerns about indoor air quality—pollutants that can build up to greater concentrations indoors than in the outdoors. When you have asthma sufferers or allergies, or if you have lots of pets, you may be even more aware of air quality. Will an air duct cleaning help resolve the problems? Air duct cleaning can make sense in that air ducts and your heating/cooling system send air through your home. That air may have dust or other particles in it, and those particles may accumulate over time. So, it makes sense to clean those areas once in a while. Do not respond to impractical claims that air duct cleaning provides huge health benefits. The research simply isn’t there to back up the claims.

When does it make complete sense to clean your heating/cooling system? Any HVAC system that shows signs of mold should definitely be cleaned. You should also search for the sources that allowed the wet in to start the mold, since it will mold again until you address the root cause. You should have your ducts cleaned if there are infestations of rodents or insects. And if you can see that dust or other material is clogging the ducts or dust actually gets spit out the registers, you are a good candidate for air duct cleaning. Are you having a hard time deciding if you need a cleaning? One place to look for help is the company that installed your heating/cooling system. They may be able to help you understand how sealed or unsealed your system is, and where possible contamination may enter. You can, of course, also ask an air duct cleaning company.

Be careful if the offer you receive is very low-priced. If you look at all the elements that must be cleaned in a complete service, you will see that it is no small job. In addition, the company has overhead for the proper equipment, including the vacuum systems. Often, you will find advertisements for a teaser rate, then the company piles on charges so you end up with a big bill. Avoid working with companies that offer very low rates. As far back as 1996, the EPA estimated that a good air duct cleaning job costs between $450 and $1,000. Look for an air duct cleaning company that will provide a reasonable estimate, taking into account the size of your house and ductwork, access to the heating/cooling coils, and the entire system.

Another suspicious sign is a company that wants to set up regular cleanings. Duct cleaning frequency depends on who is living in the house and their habits and susceptibilities, what animals are present, whether there is a change in conditions (such as a sudden increase in rain and subsequent water damage followed by mold), and similar variables. Since the absolute benefits of getting an air duct cleaning are not yet completely documented, you should have it done only as needed. A quality air duct cleaning company will understand this and not try to lure you in annual contracts. Air duct companies themselves estimate that a cleaning lasts between three to seven years. This very wide range makes setting up a schedule less than helpful. Also, if you have the misfortune to encounter a poorly trained technician, your heating and cooling system runs the risk of damage.


What Tools Are Used to Clean Your Air Ducts?

When you look at air duct cleaning companies, you may come across competing claims about the value of different tools, particularly the vacuum. The vacuum may be truck-mounted or may be portable. Some claim that truck-mounted vacuums are superior, but the trade association for air duct cleaners, the National Air Duct Cleaners Association (NADCA), says that if the trade association’s standards are followed, either a truck-mounted or a portable vacuum will do the job effectively. Truck-mounted vacuums are usually more powerful, but a portable vacuum can be brought into enclosed spaces, closer to the job itself. If a portable vacuum is used and it exhausts into the house, it must have a HEPA filter to prevent particles from being released into the interior space. Your air duct cleaner may also have a use for handheld vacuums and wet vacuums, which should also have HEPA filtration.

Typically, brushes are used to agitate the equipment and loosen dust. Some air duct cleaning companies may also use an air whip, an air gun or a blowgun to loosen and move debris. However, fiberglass components can be damaged by these aggressive tools, so ask how your air duct company will manage fiberglass materials. Look for soft-bristled brushes to be used with fiberglass. Your air duct cleaner might also need tools to cut into ductwork for better access. Inspection tools might include mirrors, a camera or closed-circuit television, or a periscope.


Do You Need Training to Clean Air Ducts?

The air duct cleaning company should be licensed regardless of where it operates. This is because for a proper cleaning, your air duct cleaner must have a C20 contractor’s license from the California Contractors State License Board (CSLB). The C20 license is granted to those who build, maintain and repair heating, air conditioning, and ventilation equipment. In a proper air duct cleaning, the cleaning includes removing and cleaning the blower motor components, then reinstalling them. Since the blower motor is part of the HVAC system, the air duct cleaning company should be properly licensed to work on HVAC systems. The state of California mandates that contractors include their license number in any advertising. You will notice that many air duct cleaning companies do not have a license. You should ask them why not and what components they include in the air duct cleaning service that they provide.

You may want to consider looking for air duct cleaning companies that belong to the National Air Duct Cleaning Association (NADCA). Members of the association will perform work to the association’s defined standards and adhere to their ethics commitments. The companies also pledge to hire at least one certified Air Systems Cleaning Specialist (ASCS).


Looking for a Responsible Air Duct Cleaning Company

Look for an air duct cleaning company that offers good customer service. Like all contractors, air duct companies should expect you to take common sense steps during the hiring process. Ask two or three contractors for an estimate. Make sure the estimate is for your particular situation, not a general estimate.

Ask for the company’s licenses and certification, as well as how long the company has been in business. California requires any company with employees to have workers’ compensation insurance, which will protect you if a worker is hurt on your property. Also, California requires contractors to be bonded, so check for that. The company should have general liability insurance, though the state does not mandate it. Ask for a written agreement before work is started. Ask how long the job may take and how many people it may require, and make sure any estimate covers those variables. Ask how the company plans to protect any pets and the house during the cleaning process.


What Does an Air Duct Cleaning Company Do?

Now that you’ve decided to have an air duct cleaning, you should know what the service entails. First, the company you hire should demonstrate safety awareness. Prior to any air duct cleaning, the air duct cleaning company should look to see if asbestos is present. If there is asbestos, it must be handled according to the state guidelines.

Ensure that your air duct cleaning company has the proper tools. A vacuum alone is not enough, since tools such as brushes or blowguns should be used to agitate debris, in concert with the vacuum, which will pull the debris out of the heating or cooling system.

Be sure the company plans to clean all the appropriate components. These include the supply and return air ductwork. The supply air duct sends heated or cooled air to the rooms, while the return air duct sends air back to the heating or cooling mechanism. The supply registers, return air grilles and any diffusers should be removed, cleaned, and reinstalled. The supply and return plenums need cleaning. The plenums are boxes that are close to the coil for the heating or cooling device and connect to the rest of the ductwork that travels throughout the house. Check especially for moisture on the supply plenum, which can lead to mold. (The supply plenum sometimes gets damp if condensation from the coil is not properly drained.) Be sure that the heat exchanger’s air-stream side and the secondary heat exchanger get cleaned. The blower motor and its housing and assembly should be removed, cleaned, and reassembled, leaving no oil or other dirt on the blades and the entire blower compartment clean. The evaporator coil, drain and pan should all be clean, and the coils should not be damaged after the cleaning. Any air filters should be replaced with filters that match those recommended by the heating/cooling system’s manufacturer. The air cleaner should also be washed.


Do Chemicals Have a Place in My Air Duct Cleaning?

If your air duct cleaning company follows trade association standards, they may opt to clean your evaporator coil using chemicals and water instead of vacuuming. Ask your technician if he or she will use a chemical to clean the coil. Otherwise, chemicals may be or recommended as preventatives against mold and bacteria. Be cautious about allowing the use of such chemicals. Realize that releasing them into the air in your home may cause reactions among the occupants.

Chemical manufacturers must register the uses for the chemicals they produce with the Environmental Protection Agency (EPA). The chemicals cannot be used for anything besides the registered use. There are only a small number of chemicals that are registered for preventing bacteria and mold. Any such chemical must be applied as described on the label or not applied at all. For example, if the label requires rinsing with water, it should not be used, since it is not a good idea to introduce water into your ductwork. Note that chemicals for preventing mold or bacteria are only for use on bare sheet metal. Much ductwork today includes fiberglass duct board or is flexduct (which includes fiberglass) or a metal pipe lined with fiberglass. Where fiberglass is involved, the material should be replaced if it has mold or other contamination, since there are not products approved to clean fiberglass.

Make sure the chemical is really necessary. Ask the air duct cleaner to show you the mold or other microbial growth. Not everything that looks like mold is mold. If your air duct cleaner shows you material from inside your ducts and claims that it is mold, get it checked by a laboratory to prove that it is mold. The chemical that will be applied should be shown to you so you can verify that it is approved for use in your situation. Chemicals to stop microbial growth should always be a last resort. Speak with your air duct cleaner to find out why he or she cannot simply remove the existing growth and then address the source of the problem (improper evaporation drainage, for example) to prevent it from returning.

Beware of any sealant that promises to trap duct and particles and prevent them from entering the air. In most cases, such sealants do not work. First, they are often sprayed into the ducts, making proper coverage impossible. Besides, a sealant may harm ducts built from fiberglass, reducing their ability to manage acoustics and possibly even harming their fire retardation abilities and voiding the manufacturer’s warranty. The EPA, the NADCA, the North American Insulation Manufacturers Association (NAIMA) and the Sheet Metal and Air Conditioning Contractors’ National Association (SMACNA) do not typically recommend using sealants that are supposed to trap dust. You may encounter cases when sealants are appropriate. Some sealants may be appropriate when repairing damaged fiberglass insulation or fire damage in the ducts. A sealant should never be applied on top of wet, dirt or mold.