Ventilation, most simply defined, is the replacement of bad air with good.
It’s typical for homes to develop bad air due to all sorts of things—dust, pollen and other pollutants blown in from outside; formaldehyde, volatile organic compounds (VOCs) and other unhealthy substances too often produced by today’s household cleaners and furnishings; and carbon monoxide, nitrogen dioxide, mold-causing moisture, among other things, generated during everyday activities like cooking, bathing and even breathing.
Homes are more sealed up than ever now, too, thanks to widespread use of year-round heating and cooling systems as well as the quest for energy efficiency. Unfortunately, buttoned-up homes easily trap and contain all those things that negatively affect the quality of your home’s air.
Exhaust fans draw air from a particular location and vent it to the outside. (A practice called “spot ventilation,” FYI.) Kitchens and bathrooms should both have exhaust fans. Use the kitchen’s fan even if it’s noisy—that’s the sound of good ventilation, after all. Turn the bathroom fan on after bathing for 45 minutes, minimum.
When outdoor air is cooler and drier than your indoor air, by all means, open the windows and let that fresh air flow through! If it isn’t windy out, use a window or whole-house fan to better encourage air movement, both into and out of the home. If your home has more than one level, experiment with the so-called “stack effect” or “chimney effect” on cool nights for better airflow. Open a window down low, to let the cool air in, and one higher up, to move the warm air out.
Most heating and cooling systems don’t completely eliminate moisture in the air, so use a whole-home or single-room dehumidifier to help reduce mold potential. Change your air filter at least four times a year—more often if your home has air quality issues. And clean carpets with a HEPA-filtered vacuum regularly.