How Do Air Ducts Get Dirty?

You might think that you keep a pretty clean house. And that might be true… to an extent! However, airborne contaminants in your home land visibly on surfaces, but also circulate with airflow currents forced by your HVAC system. Every time we open the door, walk across carpeting, scratch out dry skin or unroll paper towels, we contribute to airborne dust. Of course pets and dust emitting activities such as remodeling make the problem worse. In fact, it is not uncommon to find construction dust in a home’s heating and cooling system years after the house was built (gross, right?). On average, this contaminated air recirculates throughout your home five to seven times per day.

If you are witnessing pollen and dust on your shelves, those same materials are travelling through your air ducts and into your HVAC filter. Other common airborne substances include smoke, mold and dander from pets; it can vary based on time of year, your lifestyle and geography. If you have a moisture problem in your home, mold can also form inside your air ducts.

Many times, rodents and insects are attracted to air ducts through air returns; an unfortunate side effect to these creatures getting into your air ducts is that they can also leave waste, which can affect the general cleanliness of your air ducts.