The Health Effects of Ducted Heating: A Closer Look

An In-Depth Guide to the Adverse Health Effects of Ducted Heating

By Brittany Cotton
Reviewed by Brett Stadelmann,

You might be wondering if the forced-air heating system in your home is negatively affecting your health. The short answer is that it is entirely possible.

You might be experiencing respiratory issues, rashes, headaches, or fatigue. These symptoms can be attributed to conditioned air that is not clean circulating throughout your home. But what is causing the air to become contaminated? And what exactly are those contaminants that are making you feel unwell?

We’ll break down the potential health effects of ducted heating, what exactly may be causing these health issues, and ways you can improve the indoor air quality of your home.

Potential Health Effects of Ducted Heating

When the ducted air inside your home is contaminated with pollutants and other irritants, you could potentially develop serious health conditions with exposure to these things. Some of the most common irritants include:

  • Bacteria and viruses
  • Dust
  • Excessive dryness or moisture
  • Household cleaning products
  • Mites
  • Mold and mildew
  • Pollen
  • Volatile Organic Compounds (VOC)

Here are some, not necessarily all, health conditions that can result from these particulates.


Some HVAC systems rely on outdoor air intake. Unless filtered properly, these types of systems can introduce pollen into the home which can aggravate allergies. Dust, mites, and pet dander can also cause allergic reactions, such as sneezing and wheezing.

Further Reading: Location of Outdoor Air Intakes and Exhaust


Persons with asthma can experience symptom flares when the warm air circulating within your home is overly dry. Likewise, mold spore growth from excess moisture can trigger shortness of breath and coughing spells.


One of the most common complaints during the winter is headaches from indoor air. This often is caused by toxic cleaning products and other chemicals used for household and personal hygiene. When you continually breathe in these non-natural toxins, you can easily develop migraines or tension headaches which can be accompanied by nausea.

For more on this, see Cleaning Supplies and Household Chemicals by the American Lung Association

Respiratory Infections

Without the introduction of fresh air, ducted heat can carry bacteria and viruses, including those that cause conditions such as the flu and pneumonia. When someone in the family has a bacterial or viral respiratory infection, every cough and sneeze can spread germs that continue to recirculate through the HVAC system. It is often no surprise when everyone in the home ends up with the same infection.

Skin Rashes

In winter, warm dry air can aggravate certain skin conditions by removing moisture from the home. Moisture is important for keeping the skin hydrated. People with eczema can experience an increase in irritating rashes aggravated by the circulating dry air.

Additional Issues Due to Poor Quality Air

In addition to the common health issues mentioned from poor indoor air quality in winter, there are some other conditions that are worth mentioning.

Chronic Obstructive Pulmonary Disease (COPD) is a serious health condition that is normally caused by smoking or being exposed to smoke indoors. If you or someone in your home smokes, the condition can be aggravated by the constant recycling of smoke throughout the house.

Heart Disease has been linked to indoor air pollutants, especially Ischaemic Heart Disease. Based on research, the EPA has determined that there is a direct link between exposure to air pollution and build-up of plaque in the arteries.

Some of the lesser symptoms of exposure to unhealthy ducted warm air include red and watery eyes, nose and throat irritation, dizziness, and fatigue.

Ways to Improve Indoor Air Quality

The air inside your home may be of poor quality due to issues with your HVAC ducts. This is especially true when the air is heated and recirculated all day and night. There are some simple and some more technical things you can do to improve indoor air quality (IAQ) in winter.

Keep a Clean Environment

One of the best ways to ensure that the air inside your home is free of contaminants and irritants is to maintain a cleaning schedule. This can be small cleaning projects performed on a daily basis or thorough cleaning of the entire home one day a week. Make it fit your routine so that it isn’t overwhelming.

Start by dusting furniture and window coverings. After the dust settles, vacuum all carpets and upholstery, preferably with a HEPA filter-equipped vacuum. Wipe down solid surfaces, mop floors, and sanitize damp areas, such as bathrooms. Be sure to clean bed linens and bath towels often. Have your carpets professionally cleaned seasonally to remove pet hair, dust mites, and dirt.

Maintain Your HVAC System

It is very important to have your heater serviced by professionals at least once a year. The technician will clean the unit, tighten loose connections, lubricate moving parts, and replace filters. This is a basic tune-up that will prolong the life of your HVAC system and ensure that it is running cleanly and efficiently.

Take your time selecting the company. There are useful tools such as those at the Better Business Bureau and U.S. News that can help you find a good one.

Vintage sketch describing schoolroom air ventilation
Ventilation on the downdraught system, by impulsion, or the ‘plenum’ principle, applied to schoolrooms (1899)
Credit: Robert Boyle & Sons – Natural & Artificial Methods of Ventilation

Have Your Ducts Cleaned

Heating ducts can be a source of dust, mold, and other particulates that can be released into the air causing health issues. Having your ducts inspected and professionally cleaned with the proper equipment can remove all sorts of contaminants. This can also remove debris build-up that clogs the ducts and vents restricting the air flow inside the ducts. It is recommended that air duct cleaning be performed every 3 to 5 years.

Install a Humidifier or Dehumidifier

In winter, your home can become overly dry with constantly circulating warm air. Dryness can cause skin irritation, red eyes, and a dry cough. If your home is overly dry, consider installing a humidifier in the HVAC system to add moisture to the air. If you prefer, you can use portable room humidifiers. In summer, it is often a good idea to use a dehumidifier when the AC is running constantly.

UV Lighting Air Purification System

A more technically advanced aid in combating poor air quality is by introducing ultraviolet lighting (UV). UV lights use electromagnetic radiation to help clean the interiors of your HVAC supply and return ducts. This is similar to how the sun’s rays purify outdoor air. As the heated air passes through the ducts, the UV lights target and destroy opportunistic microbes and bacteria.

The sanitized air is then theoretically free of microorganisms that can cause disease. This system also reduces Volatile Organic Compounds (VOCs) in the air. You will benefit by breathing more easily and experiencing fewer colds and allergies. These types of purifiers are often used in medical facilities.

The Health Effects of Ducted Heating: White air ducts in an office
HVAC Air Ducts in Commercial Space
Photo by Drew Beamer on Unsplash
The control circuit in a household HVAC installation. The wires connecting to the blue terminal block on the upper-right of the board lead to the thermostat. The fan enclosure is directly behind the board, and the filters can be seen at the top of the image. The safety interlock switch is at the bottom left.
The control circuit in a household HVAC installation. The wires connecting to the blue terminal block on the upper-right of the board lead to the thermostat. The fan enclosure is directly behind the board, and the filters can be seen at the top. The safety interlock switch is at the bottom left. In the lower middle is the capacitor.
Credit: Idahoprogrammer

Importance of Clean Heated Air

It is very important to have clean air to breathe indoors in winter. We can’t do much to control the air outside, but we can improve our indoor environments by implementing some or all of the suggested solutions here. By doing so, there are several benefits that you may experience.

Fewer Respiratory Infections

With cleaner circulating warm air during cold and flu season, it is likely that you will reduce exposure to bacteria and germs. While you will still have to be mindful of anyone who is ill inside your home, your chances of also becoming sick will be lessened with air that is purified or at least less compromised.

Better Stamina

In winter, many of us workout indoors, especially in cold climates. When we exercise, we require additional oxygen for our lungs, our blood, and our muscles to perform optimally. The better the oxygen we are breathing in, the better our stamina will be and the fewer muscle strains we will experience.

Improved Sleep and Decreased Fatigue

If you have ever awakened in the night reaching for a water bottle or due to snoring, you probably realize that the air you are breathing is dry and dusty. Dry and dirty air can cause sleep apnea and excessive thirst. Adding a humidifier to your HVAC system can greatly improve your sleep.

Anti-Aging and Clearer Skin

Heated air can often be so dry that it affects the skin by depleting it of surface moisture. In turn, this can cause wrinkles, scaly rashes, and roughness. Skin that is chronically dry causes premature aging, similar to overexposure to the sun without SPF protection. Humidified heated air can be anti-aging and can help with patchy skin breakouts and even dandruff.

Enhanced Mood

There is no denying that breathing clean and healthy air can enhance health. When you feel healthy due to adequate sleep and exercise, your mood will improve. Feeling run-down, short of breath, and exhausted can often be attributed to air that is contaminated by indoor pollutants. Keeping ducts clean and well-filtered can improve indoor air quality and in turn, promote a good mood.

Clean air, blue skies and green hills

Bottom Line

If you are noticing that you are not feeling 100% during the winter months, it could be due to your forced air heating system. While you can’t see that the recirculating air inside your home is unhealthy, there will be symptoms that let you know that it is time to reach out to HVAC and duct professionals to test your indoor air quality and remedy the situation.

We have outlined many of the causes of dirty indoor air and the related health hazards. We have also offered some recommendations for improving indoor air quality in winter and the benefits of the same in this article.

And we’d love to hear your thoughts. Leave a comment below!