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"My fridge is running up the electric bill": measuring and estimating an appliance's energy use

Energy is watts multiplied by hours. DOE's method: wattage times hours used per day, divided by 1,000, gives kWh per day; multiply by days and by the utility rate for cost. A refrigerator is plugged in all day but its compressor cycles, so DOE estimates its running time at about one third of the hours plugged in. The best answer is a measurement: run a plug-in kWh meter on a 120 V cord-connected unit for a day or more and scale it up. A unit using far more than its label estimate, or running almost nonstop, points to a real fault worth diagnosing.

Cross-checked ~20 min easyBrands: All

Before you start

  • Do not put a plug-in meter on a 240 V appliance or between an appliance and an extension cord
  • Clamp-meter readings on 240 V units are taken with the cover off and power on: caution

Diagnostic steps

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OnCall Tech is a reference tool for trained technicians and can make mistakes. Always disconnect power and confirm with the manufacturer's documentation before you work.

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"My fridge is running up the electric bill": measuring and estimating an appliance's energy use · OnCall Tech