What is the purpose of applying demand factors to non-residential buildings?

• A. To ignore some loads
• B. To increase the calculated load
• C. To reduce the sum of connected loads to reflect simultaneous use
• D. To simplify by ignoring all loads

Answer: (C)

Demand factors are used to reflect that not all electrical loads in a non-residential building operate at the same time. By applying a demand factor to the sum of all connected loads, the calculated load is reduced to a realistic level that represents simultaneous use. This allows the designer to size feeders and services based on probable maximum demand rather than a worst-case sum of all loads, preventing oversizing while still meeting the building’s actual needs. Different systems—lighting, HVAC, motors—have different duty cycles and aren’t all at full load together, so the factor accounts for that diversity. Choosing to ignore loads or to increase the total load would misrepresent how the system actually operates, while ignoring all loads would be inappropriate.