ABSTRACT
Homes of have more and bigger fans than before: clothes dryers, central vacuums, whole house ventilation fans, air handlers instead of gravity fed circulation systems, stronger kitchen fans, stronger furnace fans, and central air conditioning. Building science experts believe that the key to successful weatherization is to treat the whole house as a system. It is important to understand the interdependency of the components and systems in a home and their combined effect on energy savings and health and safety issues. For every conditioned (heated or cooled) cubic feet per minute (CFM) that goes out of the house, a CFM of untreated outside air enters the home, but typically at a different location. The biggest concern is with air movement between the inside and outside of the house. Some of the forces that cause pressure differences in homes include wind, heat, and fans.
