What type of air leakage refers to the loss of conditioned air to unconditioned spaces?

The type of air leakage that denotes the loss of conditioned air to unconditioned spaces is exfiltration. This happens when the indoor air, which has been heated or cooled to maintain a comfortable environment, escapes to areas that are not controlled for temperature or humidity. The process often results in higher energy costs, as the HVAC system must work harder to replace the lost conditioned air and maintain the intended indoor climate.

Understanding exfiltration is crucial for energy efficiency and effective HVAC design, as it relates directly to maintaining the integrity of the conditioned space. It is particularly important in building design and renovation to account for potential exfiltration points to improve overall energy performance and indoor air quality.