Demand factor formula
For each load group, demand factor = maximum demand รท connected load. Expressed as a percentage, multiply the ratio by 100.
The overall calculation uses the sum of connected loads and the sum of the group maximum demands entered into the model. This is appropriate only when the entered maximum-demand figures are being used as a consistent basis for the overall comparison.
Why group-level demand factors are useful
A site can contain groups with very different utilization behavior. Lighting, HVAC, kitchen equipment, motors and general receptacles may have different peaks. Reviewing each group helps reveal where the connected nameplate load is substantially larger than the observed or assumed maximum demand.
Example
A group with 100 units of connected load and 60 units of maximum demand has a demand factor of 0.60, or 60%. Another group with 40 units connected and 35 units maximum demand has an 87.5% demand factor. The second group is closer to its connected load even though its absolute load is smaller.
Interpretation
A low demand factor means the maximum demand is a smaller fraction of connected load. A high factor means the observed or assumed maximum demand is closer to the connected load. Neither is automatically good or bad; the appropriate interpretation depends on what the connected load represents and how the maximum demand was obtained.
Important limitation
Demand factor is not the same as diversity factor or coincidence factor. Those terms describe different relationships. Do not use one metric as a substitute for another during system design.
Frequently asked questions
Can maximum demand be estimated rather than measured?
Yes. The input can represent an assumed scenario, but results should be labeled as estimates and not presented as measurements.
Can demand factor exceed 100%?
Not when the maximum demand and connected load are correctly defined on the same basis. A result above 100% should trigger a data or definition check.
Does this calculate diversity factor?
No. Diversity factor is based on individual maximum demands versus the coincident system demand and is a separate calculation.