A small well insulated home needs fresh air ventilation and supplemental dehumidification to have good indoor air quality. You need a fresh air change in 4-5 hours when occupied to purge the indoor pollutants and renew oxygen.
Checkout the Ultra-Aire 70 whole house dehu with optional fresh air ventilation. They are sponsor of this site. It connects to your conditioning ducts and will do the entire home. Maintaining <50%RH through the home while providing fresh filtered air is healthy and comfortable.
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"