Duty cycle: the assumption that changes everything

Understand how cycling appliances turn scheduled runtime into active energy use—and why a range is often more truthful than a single number.

Scheduled time is not active time

A refrigerator is connected all day, but its compressor cycles. An AC may be scheduled for eight hours while cooling actively for only part of that period. Duty cycle is active time divided by scheduled time.

Estimate with observations

Listen for compressor or element activity over several representative periods, or compare energy measured across a known time window with the appliance’s rated power. Weather and occupancy can change the result, so avoid extrapolating one unusual day across a year.

Use ranges for decisions

If a purchase decision changes only under an unrealistically low duty cycle, that is useful information. Run low, typical, and high scenarios rather than relying on false precision.

Who · how · why

How this page was prepared

PowerCost Lab publishes this page to help readers make a specific electricity-cost decision. Worked figures are recalculated from the inputs shown, assumptions remain visible, and market facts are separated from user-entered estimates.

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