For Indoor Environmental Quality credit basic Outdoor Air Ventilation, what is the maximum infiltration degree days required to be exempt from this prerequisite?

For the Indoor Environmental Quality credit pertaining to basic Outdoor Air Ventilation, the prerequisite outlines a requirement for new buildings to manage indoor air quality effectively. The concept of infiltration degree days helps determine the extent to which outdoor air is introduced into a conditioned space through unintentional openings.

Exemption from this prerequisite is granted when the expected air infiltration, indicated by infiltration degree days, is below a certain threshold. In this case, the maximum number of infiltration degree days required to be exempt from the prerequisite is 4500.

This figure reflects the recognition that buildings in regions with lower ventilation needs due to climate and temperature variations can efficiently maintain indoor air quality through their designed HVAC systems without additional outdoor air ventilation. This allows these buildings to achieve credits without the stringent requirements imposed on those with higher infiltration levels. Understanding this exemption helps in applying the LEED standards effectively, particularly in various climatic regions.