How Often Should You Clean Your Air Ducts?

Air ducts are a vital part of our HVAC systems, but it can be confusing knowing how often to clean your air ducts.

The Environmental Protection Agency (EPA) states that committing to a preventative maintenance program for our HVAC systems is essential to minimizing duct contamination.

Americans spend as much as 90% of their time indoors, where pollutants can be two to five times higher than outdoors. In Arizona, we spend a great deal of time in air-conditioned spaces during the summer months to escape the heat, and dust can be problematic in our dry climate.

If your air ducts are dirty or improperly sealed, it can affect the indoor air quality in your home, which can be especially problematic for asthma and allergy sufferers.

When to Clean Ducts

The National Air Duct Cleaners Association (NADCA) recommends ducts be cleaned every three to five years.

As the ductwork in our homes is hidden, you may be unaware of unseen damage that can impact your indoor air quality.

If you have family members with respiratory problems, allergies, or pets, you may need your ducts inspected for dirt and debris and cleaned more often.

Also, dust and debris may have gotten into your air ducts if you’ve had any recent dust-generating construction projects in your home.

Three main problems can occur in ducts that require immediate professional attention:

  1. Mold or mildew in ducts.

If your HVAC system hasn’t been well-maintained, there could be an undetected leak that results in moisture in the ducts. Moisture buildup can lead to mold or mildew in the ducts, posing a health threat and requiring immediate attention.

Visible signs of mold or mildew mean your ducts need cleaning as soon as possible.

You should have all parts of your HVAC system serviced to address the cause of the mold or mildew growth, so it’s not a recurring problem.

  1. Vermin and their debris inside the ducts.

Even small air leaks in the ducts can allow insects and other vermin to enter.  The debris they leave behind can compromise your indoor air quality and pose a health threat to your family.

If there are signs of vermin contamination in your ducts, your ducts need cleaning.

  1. Excessive dust in the ducts.

If you see signs of dust blowing out the vents in your home or your indoor air quality has suddenly decreased, it may be time to clean your ducts.

Air ducts may also leak, allowing dust to build up inside. Ducts should be sealed and insulated in all non-airconditioned spaces, such as attics.

A poorly maintained HVAC system can also accumulate dust that blows into your home.

Excessive dust is a sign that your ducts probably need cleaning.

It’s best to leave duct cleaning and repairs to HVAC professionals who have the specialized equipment and knowledge of HVAC systems to do it properly.

What We Can Do for Our Ducts

While duct cleaning should be left to the pros, there are things we can do to keep our HVAC systems running smoothly.

  1. Change air filters regularly.

Air filters filter the air that comes through the ducts and into your home, so they also play a significant role in indoor air quality. Clean air filters also ensure the efficiency of your HVAC system, so you should change your filters as often as once a month in the summer.

Air filters have different ratings based on their ability to capture airborne particles.

Air filters have what’s known as a MERV rating. MERV stands for Minimum Energy Reporting Values and measures an air filter’s ability to capture particles sized between 0.3 and 10.0 microns.

MERV ratings range from 1-20, and the higher the rating, the more particles such as dust the filter can capture.

The EPA recommends using the highest efficiency air filter recommended by the manufacturer of your HVAC system.

According to the American Society of Heating, Refrigerating and Air Conditioning Engineers (ASHRAE), the best rating for residential systems is MERV 13.

However, your HVAC system may not be able to handle a higher MERV-rated filter, so check with an HVAC pro before upgrading to a filter with a higher MERV rating.

Using a filter with a higher rating than your system can accommodate may lower the airflow and force your HVAC system to work harder.

Regularly changing the air filters is one of the simplest and most effective things you can do to help your HVAC system run smoothly.

  1. Have your HVAC system regularly maintained.

Ducts are a part of your overall HVAC system, and all HVAC systems require regular professional maintenance to work at peak performance. As hard as our air conditioners work in Arizona, neglecting maintenance will only lead to costly repairs, higher energy bills, and a shorter lifespan for your system.

Chas Roberts has a 26-point maintenance checklist to keep your HVAC system running in top shape. The cooling season checklist includes:

  • Check refrigerant levels
  • Inspect disconnect switch
  • Clean condenser coil
  • Test safety controls
  • Lubricate all moving parts
  • And more

Regular professional maintenance will prolong the life of your equipment, keep your HVAC system working at maximum efficiency, and ensure the air quality in your home stays as high as possible.

  1. Know when it’s time to replace an aging air conditioner.

Aging air conditioners decline in efficiency until they eventually fail. If your air conditioner is over ten years old, is losing efficiency, and needs more repairs, it may be time to purchase a new unit.

If the ductwork circulating the air from your older air conditioner is also faulty, you’ll most likely have poor indoor air quality that can threaten your health.

A Chas Roberts pro can help you choose a new, more efficient A/C system to replace your older air conditioner.


Air ducts are a crucial part of your HVAC system, and having regular professional maintenance of the entire system will help minimize duct contamination. Ducts’ performance, like that of air conditioners, can decline over time and affect the air quality in your home.

Leaking, damaged, or excessively dusty ducts can compromise the health of your household and should be dealt with promptly.

Air conditioner and duct repairs are not do-it-yourself projects and should be handled by a qualified HVAC professional.

A well-maintained HVAC system and duct cleaning every three to five years, as recommended by NADCA, will help keep your system running at peak performance.

Chas Roberts is the oldest and largest residential HVAC company in Arizona and has been in business for over 75 years.  Contact us for affordable, reliable service.