Why is ventilating houses so important?
Nearly all homes contain building materials, furnishings, decorating items, and cleaning products that outgas pollutants into the indoor air. Ventilation can dilute the concentration of those pollutants. But, even if totally inert, safe alternatives are used, there’s one pollution source that can’t be eliminated—people. Because of normal, everyday human metabolism, we all release various gases such as carbon dioxide, water vapor, ammonia, methane, etc. If allowed to build up indoors, these can make a house odorous and uncomfortable. Plus, we all need a supply of fresh air indoors to replace the oxygen that gets used up. If you have an unhealthy house (one built, maintained, and furnished with unhealthy materials), you’ll probably need a powerful ventilation system to dilute the concentration of all the indoor pollutants. But if you have a healthy house, the ventilation system’s primary job will be to dilute the metabolic pollutants released by the occupants—so it doesn’t need to be as
