The maximum allowable amount of R-408A in a 2000 cubic-foot Institutional Occupancy is _____ lbs.

In the context of the North Carolina Mechanical Code, the maximum allowable amount of refrigerant in a given space is determined by the type of occupancy and the refrigerant’s classification. For institutional occupancies, there are specific guidelines that dictate the maximum refrigerant charge allowed based on the cubic footage of the space.

R-408A is classified as a refrigerant that is typically used in various types of cooling systems. The limit for institutional occupancies, especially when considering a volume of 2000 cubic feet, often falls under specific regulations that are designed to ensure safety and compliance with fire and health standards.

The correct answer of 21 pounds aligns with the code stipulations that allow for this amount while taking into consideration factors like ventilation, the potential for leaks, and the need for safety margins in environments where there may be vulnerable populations. Understanding the capacities and restrictions for refrigerants like R-408A in institutional settings is critical for compliance with safety regulations while ensuring efficient operation of cooling systems.

The other options listed, while they may represent limits for different categories or sizes of occupancy, do not meet the established maximum for institutional occupancy in this specific scenario. This makes the 21-pound limit the ideal and compliant choice for maintaining safety standards in such environments