Indoor Air Quality is generally worse than most people want to believe. Indoor pollutants come from a sources that release gases or particles into the air. Another factor in IAQ is poor ventilation. Proper exchanges of indoor and outdoor air must occur to dilute indoor emissions, and bring fresh air into the home.
New homes are built “tight”, while older homes leak. Most new homes have air exchangers that bring fresh air in, and remove the old polluted air. This process is very important to maintaining “fresh air” in the home.
Older homes, especially those that have not been remodeled, have a natural draft that brings some fresh air into the home. Opening a window for 5-10 mins. daily, will help bring in fresh air.