Ventilation systems that circulate air for heating and cooling also circulate contaminants. Indoor pollutants are often bothersome and nothing more, but some can cause illness and worsen respiratory ailments. Benefits of addressing indoor air quality with a humidifier and/or air purification system can include reducing flare-ups of respiratory issues, decreasing eye irritation, improving HVAC airflow, and enhancing indoor climate control. Air purifiers work with your HVAC system to remove microscopic pollutants that aren’t seen with the naked eye. Volatile organic compounds (VOCs) can affect the indoor air we breathe. Cleaning products and personal care products we use release VOCs. Pesticides do the same and are usually tracked into homes on our shoes. Humidity affects indoor air quality in various ways. For instance, dry air in winter makes it easier for viruses to be transmitted.