What is the interior lighting load for a school building with 175,000 square feet of floor space?

To determine the interior lighting load for a school building, the National Electrical Code (NEC) provides guidelines for calculating lighting loads based on the square footage of the facility. For educational facilities, the typical lighting load is often calculated at a rate of 3 watts per square foot.

In the case of a school building with 175,000 square feet of floor space, the calculation would be as follows:

175,000 square feet x 3 watts/square foot = 525,000 watts.

To convert watts to volt-amperes (VA), which is typically used for calculating electrical loads, it is standard to assume that 1 watt is equal to 1 VA for purely resistive loads. Therefore, 525,000 watts is equivalent to 525,000 VA.

This calculation aligns with option C, which indicates that the interior lighting load for the school building is 525,000 VA. This answer is reinforced by applying the NEC guidelines for educational facilities, substantiating that option C reflects an accurate assessment based on the square footage provided.