Ventilation is an effective way to improve the air quality in your home because, typically, the outdoor air quality is better than the indoor air quality (IAQ). Learn more here. Bringing in fresh air from the outdoors will help remove carbon dioxide (Co2), carbon monoxide (CO), and other volatile organic compounds (VOCs). However, it can bring in pollutants such as particulate matter (PM), pollen, dust, and debris, increasing the need for good filtration. Below are ventilation solutions ranked in order of effectiveness.
Opening windows for ventilation
The simplest form of ventilation is opening your windows and turning on the AC fan. This will bring in fresh air from the outdoors, helping reduce Co2, CO, and other VOCs in your home. The downside is that it will bring in dust and particulate matter (PM), which can cause your home and HVAC system to get dirty faster. This results in more frequent filter changes and the need to clean your HVAC system's internal components and ductwork more often.
Whole-house fans for ventilation
Installing a whole-house fan is a great way to improve the IAQ in your home because it will bring in fresh air from outdoors and exhaust it into the attic. This is better because your HVAC system won't get dirty as fast, and it will reduce the temperatures in the attic, resulting in better energy efficiency. Additionally, whole-house fans can give your home a fresh air exchange in minutes and quickly remove smells and odors. However, your home may still get naturally dusty due to the dust and particles that make their way into the house with the fresh air.
Energy and heat recovery Ventilators (ERV/HRV)
The higher-end ventilation solutions are energy recover ventilators (ERV) and heat recovery ventilators (HRV). An ERV or HRV does quite simply what it is called, recovers the energy already used to cool or heat the home, as it brings in fresh air from the outdoors during the ventilation process. It essentially ventilates your home while maintaining optimal energy efficiency. As a result, your HVAC system won't work as hard to maintain your home at the desired temperature. Many ERVs and HRVs also filter the air, reducing the amount of dust and other PM that makes its way to your home and HVAC system.
Ventilation for humidity control
Ventilation for controlling relative humidity is possible when outdoor and indoor conditions permit. Colder temperatures can hold less moisture, and hotter temperatures can retain more moisture. Since relative humidity is determined by the temperature and amount of moisture in the air, you can cause a drop or rise in relative humidity with properly designed ventilation. Learn more about humidity control.
The bottom line
Like every IAQ solution, there are pros and cons to each. Ventilation is great for removing harmful gases and VOCs from your home. You can get a fresh air exchange in minutes with a good ventilation system. You can opt to open your windows and turn on your blower fan. However, this will result in more frequent filter changes and HVAC system cleanings. Another option would be to choose a more advanced ventilation system such as a whole-house fan or ERV/HRV. This can help eliminate odors fast and help improve your home's energy efficiency. Whatever you decide, it is best first to understand what pollutants you have in your home. For this, we recommend purchasing an IAQ monitor. An IAQ monitor is a device that you can place in any room throughout your home, and it will let you know the IAQ in real-time. Once you have decided how you want to tackle any IAQ pollutants in your home, consult with an HVAC professional. Sources: Relative Humidity Moisture control and ventilation - WHO Guidelines for Indoor Air Quality - NCBI Bookshelf. How much ventilation do I need in my home to improve indoor air quality? | US EPA