This report provides data and conclusions about the actual performance of different types of ventilation systems as installed and operated in relatively airtight homes. Overall, this study found that total ventilation is not a determining factor in ventilation effectiveness. A key factor is the ventilation delivered to each occupied space. This is coupled with a number of other influencing factors such as house size, occupant density, airtightness, and the presence of a whole house air circulation system such as central forced air. Other factors that affect ventilation performance include humidity, home occupant education and type of heating system.
