All homes need fresh air intakes for the furnaces and the occupants. Your bath fans, kitchen hood, and clothes drier need fresh air to function. In the past we ignored fresh air. Today, most state codes suggest a specific amount of fresh air change to purge indoor pollutants and renew oxygen.
Regards TB
Bear Rules: Keep our home <50% RH summer, controls mites/mold and very comfortable.
Provide 60-100 cfm of fresh air when occupied to purge indoor pollutants and keep window dry during cold weather. T-stat setup/setback +8 hrs. saves energy
Use +Merv 10 air filter. -Don't forget the "Golden Rule"