Angie's LIST Guide to
Air Duct Cleaning & Air Quality

The air you breathe indoors can become more polluted than outdoor air because it's trapped inside, allowing contaminants to accumulate. Many HVAC companies offer air duct cleaning services, but there's no scientific proof that air duct cleaning improves air quality.



Air duct cleaning

Many HVAC repair and maintenance companies also offer air duct cleaning services, which typically cost $300 to $500.

 Is air duct cleaning necessary?

Angie's List members share their experiences and opinions on air duct cleaning. Read more

Some companies specialize as air duct cleaners. They generally recommend having air ducts cleaned every 3 to 5 years, or even more frequently to reduce pollutants in the air.

However, the U.S. Environmental Protection Agency warns that there is no scientific evidence that cleaning air ducts regularly improves air quality, and some HVAC professionals say it is a waste of money.

Yet some allergy sufferers, including Angie's List members, have reported that having their ducts cleaned has led to reduced allergy symptoms and cleaner air.

Although the EPA does not recommend routinely hiring air duct cleaning services, it does suggest it be done when there are specific reasons for doing so. This would include factors such as:

  • You see substantial quantities of visible mold growth within the heating ducts or present on other parts of your home's HVAC system.
  • Pests such as mice, rats or insects have infested portions of the duct system.
  • Excessive amounts of dust or debris clog the duct system and release dust or debris into the home through the vent registers when the system operates.

The National Air Duct Cleaners Association agrees with most of the EPA's stance on air duct cleaning with one exception -- it does recommend routine work by quality air duct cleaners every few years.

According to the NADCA, consider the following when making a decision whether or not to hire an air duct cleaner:

  • Smokers in the household
  • Pets that shed high amounts of hair and dander
  • Water contamination or damage to the home or HVAC system
  • Residents with allergies or asthma who might benefit from a reduction in the amount of indoor air pollutants in the home's HVAC system
  • After home renovations or remodeling
  • Prior to occupancy of a new home

Avoid duct-cleaning scams

When you hire someone to put up wallpaper or build a fence, it's easy to see whether it's a good job. But with services like air duct cleaning, there's much more risk of fraud because the homeowner can't easily check the work. A disreputable company may not have the proper equipment to do a quality air duct cleaning job, may overcharge you, may leave the ducts dirty or filled with debris and may even do costly damage to your home's HVAC system. Some companies entice you with very low offers, such as $59 for a whole-house cleaning, then pile on extra charges. 

When you join Angie's List you have access to member reviews and ratings of duct cleaning services located near you.

Poor air quality sources

Indoor air pollutants from combustion devices

If your home uses a combustion-based furnace such as natural gas-fired furnace or an oil-burning furnace, these heating systems produce pollution particles from that combustion cycle. Other heating devices such as gas stoves, space heaters, wood-burning stoves and dryers will also produce pollution particles that can affect indoor air quality.

If your home’s HVAC system is installed properly and is up-to-date on maintenance or repairs, these pollution particles should be expelled from the furnace and vented through the exhaust or chimney.

However, if your home’s chimney or exhaust vent are not sealed properly, combustion byproducts such as carbon monoxide and nitrogen dioxide can enter your home’s air and cause symptoms such as dizziness, headaches, irritation of the mucous membranes in the eyes, nose and throat, and, in the case of carbon monoxide, even death.

Controlling pollutants from combustion devices

The most effective way to control indoor air pollution from combustion or heating devices is to make sure they’re used and maintained properly. The EPA recommends that you make sure there’s adequate ventilation in any area where a fuel-burning or heating device is being operated. If and when you use a heating or fuel-based device, make sure that it’s properly installed and up-to-date on maintenance and repairs.

Volatile organic compounds (VOCs) from household items

According to the EPA, volatile organic compounds or VOCs are chemicals that can be commonly found in household products such as cleaning products, paints, chemical strippers, waxes and pesticides. Other in-home products that can produce VOCs that contribute to poor indoor air quality include floor coverings, furniture, electronic equipment, air fresheners and dry-cleaned clothing.

VOCs from household items can be especially hard to pinpoint as the cause of poor indoor air quality because the VOCs naturally evaporate into the air when the products are used or stored.

Controlling VOCs from household items

The negative impact of VOCs on indoor air quality can be minimized by adhering to a few common sense principles. For instance, when using a cleaning product or painting in the home, always make sure there’s adequate ventilation and fresh air by opening windows, using fans or making sure the air is expelled.

Follow manufacturer’s direction when using cleaning products and never mix any cleaning products that aren’t designed to do so. Make sure all chemical products are stored according to the directions on the label.


One of the easiest indoor air quality factors to control is the negative effects of smoking tobacco products indoors. Not only does smoking indoors produce a foul odor that can linger in upholstery, clothing and carpeting, secondhand smoke can cause cancer, serious respiratory illnesses and aggravate asthma. Children are especially vulnerable to secondhand smoke.

Controlling secondhand smoke

The most effective way to prevent secondhand smoke from contributing to poor indoor air quality is to never smoke indoors.  If any of your home occupants smoke indoors, ask them to do so outside. The same goes for visitors who may smoke.

Mold & Radon

Molds are ever-present in the air we breathe both indoors and out. However, it takes two primary conditions for mold to be able to flourish within the home: moisture and darkness. Once established, inhaling or coming into contact with spores produce by molds can irritate the nose, skin and eyes, and even cause asthma attacks.

Radon is another naturally occurring source of poor indoor air quality. A byproduct of the degradation of uranium in the the soil and stone below a home’s foundation, exposure to radon is the second leading cause of lung cancer in the United States.

Should you test your air?

If you’re concerned about the quality of your indoor air, you should examine a number of issues before turning to costly indoor air quality testing. Because there is not one comprehensive indoor air quality test, hiring a firm or purchasing a multiple test kits prior to eliminating possible sources of poor indoor air quality can be a costly and time-consuming exercise.

Cancer risks from radon

However, due to its strong correlation to lung cancer, it’s strongly recommended that homeowners test their homes for radon, especially when moving into a new home or occupying a home where no radon mitigation system exists. Homeowners concerned about carbon monoxide can purchase carbon monoxide detectors that signal when unhealthy amounts of the gas build up.

The EPA says that health problems can be one of first indicators of an air quality problem, especially if the appearance of symptoms coincides with a recent move to a new residence, a recent remodeling project or a recent application of pesticides. It recommends consulting with your health provider or local health department to help determine if poor air quality may be the cause of health symptoms.

Air pollution sources

Another step the Agency recommends is identifying potential sources of air pollution within the home. Taking a survey of your home and identifying where heating systems are located, how chemicals are stored and how well-ventilated individual rooms are can provide an avenue for improved air quality, even if those areas aren’t the actual cause for poor air quality.

If you’ve taken the above steps and still want to undertake testing for individual air pollutants, contact your local health department for guidance on how to begin evaluating your home’s air quality with the help of professionals.

Know what tests you need

If and when you elect to test your home’s air, make sure you have clear goals in mind – it’s one way to avoid unnecessary testing or expense. For instance, performing a series of tests to answer the question “Does my home have poor air quality?” can be much more expensive and time-consuming than testing based on the specific question such as “Does my home’s air have unhealthy levels of mold spores?”


Should I have the antimicrobial/antibacterial treatment done that most companies seem to offer as standard protocol? One company told me that they do not do this treatment because there isn't generally enough moisture in the HVAC system to create mold/mildew.

It's 11 years plus in the industry I have only had to sanitize two systems both were slab systems that were in concrete and could be cleaned with a different method than normal duct cleaning. We were able to use water to rinse out the disinfectant. Would you use a chemical on anything else you use to eat or drink with and not rinse it off? The ducts in your home should be thought of as your homes heart and lungs and breathe the same air that you do. And just like us we wouldn't use bad chemicals in our lungs and heart. Sincerely Sean M.

I read your reply that you sanitzed two systems that were slab systems which were concrete. I have a property in Philadelphia that is built on a slab with the ducts located in the concrete. I am interested in having the ducts cleaned. Could you recommend how I could contact a company that would clean the ducts with the appropriate method.
Thank you,

A company that is scheduled to clean my ducts (vents and air intake ducts) is planing on using a spray called microban to sanitize the vents and ducts. Do you know if that product is safe to use and will it have lasting positive or negative effects on the air that I will breath? Thank you

Is a product called microban safe to use in air ducts ( vents and intake ducts) in your home and does it have lasting negative or positive affects? Thank you.

We have been ill for 5 weeks. I have children and have noticed we all have been breathing better after cleaning of the air ducts.

At first it seemed to be mold, but maybe mold can come through the air duct? I do not know. All I know is that the change has been greatly appreciated.


Having your air ducts periodically cleaned is always a good idea. You will benefit from less brokdowns and a cleaner system.

A great read

DO NOT USE! This is chemical that has carcinogen components not approved by the EPA for residential use. The National Association of Ductworkers also does not recommend user of any sanitizer in your ducts. While many air duct companies will say that it is not harmful or dissipates quickly it is a lie.

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