Infiltration is measured in terms of how many what per hour?

Infiltration specifically refers to the process by which outside air enters a building, often through cracks, openings, and other unintentional leaks. This air exchange is crucial for understanding a building's air quality and energy performance.

Measuring infiltration in terms of air changes per hour is a standard practice in the field of building science and energy efficiency. An air change refers to the volume of air that replaces the indoor air within a space in one hour. This metric helps quantify how often the air within a building is being exchanged with outside air, which is important for assessing ventilation needs, thermal comfort, and overall indoor air quality.

The other options do not provide a relevant measure for infiltration. “People” does not relate to air movement, “units” is too vague, and “degrees” pertains to temperature rather than air flow or quality. By focusing on air changes per hour, we can accurately gauge infiltration rates and their impacts on building performance.