Read temperature before moving the dial
The FDA recommends using an appliance thermometer because many refrigerator controls do not show the actual storage temperature. Follow the appliance manual for setting changes and the time allowed for temperatures to stabilize. Check the freezer separately; the FDA guidance specifies 0°F or below.
Write down the original setting and thermometer reading. If temperatures are unreliable or food is not being kept safely cold, seek an appliance check or notify the landlord. That situation is not an energy experiment.
Avoid an instant before-and-after conclusion
If a safe adjustment is appropriate, record energy across several representative days on each setting. Note room temperature, shopping days, door openings and unusual loads. A warm grocery delivery or a hotter kitchen can change the comparison.
Do not treat one compressor-on watt reading as the daily average. Refrigerators cycle, so cumulative kWh over a known interval gives a more useful cost estimate than multiplying a peak reading by 24 hours.
Translate a small difference honestly
Suppose two comparable observation periods suggest 1.10 and 1.00 kWh per day while safe storage temperatures are maintained. The hypothetical difference is 0.10 kWh per day, about $0.54 over 30 days at $0.18/kWh.
That estimate does not prove the dial change caused the difference. Repeat the observation under similar conditions and round the result sensibly. Do not promise a fixed percentage saving across refrigerators, kitchens or seasons.
Check other causes of unnecessary work
ENERGY STAR advises appropriate temperature settings, sound door seals, separation from heat sources and adequate air circulation. Start with visible, accessible checks and the model’s instructions. Keep groceries organized so that you can find them without prolonged searching. For a rental appliance, document problems with dates and photographs for the responsible party. A clear maintenance report can be more useful than repeatedly making the thermostat colder to compensate for a fault.
Choose your next step
Continue with the question that matches your next decision:
Sources & further reading
Numerical examples are illustrative unless explicitly described as measured. This guide does not claim hands-on product testing. Read the methodology and editorial disclosure.