Ventilation is an important factor in indoor air quality, and it’s different from simply circulating the air in your house with a fan, filter or not. It requires fore thought if it is to be done effectively and mindful of energy costs.
Poor ventilation may not be noticed at first glance and your indoor air may seem just fine. The best time to check your indoor air quality is when you first enter a home, usually within the first five minutes before you become accustomed to it…that is, for those indoor air quality items that have an odour in the first place or are in sufficient quantities to even be noticed. Some indoor air contaminants can effect you but not be detected by the nose. Ventilation can also be helpful with condensation & humidity.
Exhausting stale indoor air seems easy enough. Adding fresh replacement air however can be the real trick. Opening a window for a short period of time can work but it’s not always effective or cost effective say in winter, and air circulation is also needed. Mechanically exhausting air with bathroom / kitchen fans may take several hours a day and cause combustion appliances to not operate as intended. Air exchangers work great and are quite cost effective in replacing stale indoor house air with fresh outdoor air e.g. heat recovery ventilator (HRV), energy recovery ventilator (ERV).
If you’re unsure about your indoor air quality and ventilation, consult a professional.