For every 1 CFM of exfiltration, there must be an equal amount of what?

When considering the balance of air movement in a building, the principle of air pressure and the conservation of mass come into play. For every cubic foot per minute (CFM) of air that exfiltrates (flows out) of a building, there must be an equal amount of infiltration, which is the air entering the building. This principle highlights the natural flow of air due to pressure differences, ensuring that for any air lost, an equivalent amount must enter to maintain equilibrium.

This relationship is crucial when assessing a building's air tightness, ventilation needs, and overall performance. If there is excessive exfiltration and not enough infiltration, the indoor environment can become negatively affected, leading to potential issues such as increased energy costs, discomfort due to temperature imbalances, and compromised indoor air quality. Understanding this relationship is essential for effective building performance assessments and implementing measures for improved efficiency and comfort.