There are a number of sources that poor indoor air quality can originate from. For instance, pollen, pet dander and other allergens can make their way into your home from the outdoors, simply due to an open door or even a clogged HVAC air filter.
Your indoor air quality can also be negatively impacted by the cleaning products that you use, as well as seemingly harmless odors from cooking and baking, something that has been done in excess in recent weeks. Given that it’s winter, you can probably add in the use of your fireplace as well as the use of scented candles as adversaries to your indoor air quality.