A simple way to support indoor-air quality is to keep the HVAC filter clean, the ducts clear
https://ventcleanhub868.quillnesty.com/posts/how-to-improve-hvac-airflow-in-a-home-without-replacing-the-entire-system
A simple way to support indoor-air quality is to keep the HVAC filter clean, the ducts clear, and the system serviced as recommended.