Poor Indoor Air Quality and Ductwork Issues: What's the Connection?Poor indoor air quality (IAQ) in your Grand Traverse home can have a negative effect on your comfort and health. Poor IAQ can be traced back to problems with your home’s ductwork. Read on to learn more about some of the common duct issues that affect indoor air quality. 

Leaks in Return Ducts

Air ducts that are leaking or disconnected on the return side of the HVAC system can draw in undesired particles while the system is running, including household dust, mold spores and insect droppings. All of these can aggravate asthma or allergy symptoms and cause other health problems.

Because many return ducts run through unconditioned areas like crawl spaces or attics, the leaks can draw in extra moisture, which can raise indoor humidity and make you less comfortable.

Supply Leaks

When there are air leaks in the supply ducts allowing conditioned air to escape into unconditioned areas, the greater volume of air entering the return ducts could lead to negative pressure forming inside your home. This can suck contaminants into your home from the outdoors through any available openings, including drafty windows, poorly sealed doors and any holes in the exterior walls like those for pipes or electrical lines. This can allow pollen, dust, smoke and other outdoor pollutants to enter your home.

Increased Humidity

Air duct leaks can draw in excess moisture and raise the humidity in your home. Not only does this make you less comfortable, but it can also encourage mold, bacteria and other microorganisms to start growing in your HVAC system and your home. Certain species of mold and bacteria can cause serious health problems and may require professional removal services.


Pressure imbalances caused by leaking air ducts could lead to a dangerous situation known as backdrafting, where the combustion gases from appliances like water heaters or furnaces are drawn into your home or HVAC system instead of exiting through the flue system. This can result in high levels of potentially-deadly carbon monoxide, along with other health concerns.

For information about improving poor indoor air quality, contact Team Bob’s Heating Cooling Plumbing. We proudly serve the Grand Traverse area.

Our goal is to help educate our customers in Traverse City, Michigan and surrounding areas about energy and home comfort issues (specific to HVAC systems).  For more information about ductwork and other HVAC topics, download our free Home Comfort Resource guide.

Credit/Copyright Attribution: “Bernard Zajac/Shutterstock”