Many people set their fridge way too cold, 4 °C instead of recommended 7 °C. Every degree too cold costs 6% more power. On a yearly bill of 100 € for the fridge that means: wrong temperature = 18 € waste.
Step by step
Refrigerators have a thermostat that controls temperature with refrigerant. The colder you set it, the longer the compressor (the motor) runs per day, more power. The physics: temperature difference to surroundings × runtime = energy requirement. 7 °C is completely sufficient for most food (meat lasts just as long). -18 °C in the freezer is mandatory (legionella protection). In between: 7-8 °C up top is enough.
Source: co2online, about 6% more consumption per 1 degree too cold
Step by step
- 1. Buy thermometer (digital, ~5 €)At DIY store or supermarket, get a small digital thermometer with magnet. Place it in the center of the fridge (not directly on the back wall where it's colder).
- 2. Wait 24 hoursThermometer in, close fridge door, wait at least 24 hours until temperature stabilizes. Then read it.
- 3. Turn dial until 7 °C is reachedInside the fridge (often at back) is a dial with numbers 1-5 or -/0/+. Experiment: if it shows 8 °C, turn one click colder. Always wait 24 h before trying again.
- 4. Freezer: -18 °C is standardIn the freezer compartment it can be -18 °C (legionella inhibition). If your combo has separate temp control below, set to -18 °C.
- 5. Check once per seasonIn summer it can get warmer (higher ambient), in winter colder. Check thermometer 1-2x per year, takes 30 seconds.
Worked example
Before: Example: refrigerator thermostat set to 3 °C, consumes 90 kWh/year = 22.50 €/year at 0.25 €/kWh.
After: Set to optimal 7 °C: 78 kWh/year = 19.50 €/year (6% less ≈ 3 € savings/year). For an average household with larger fridge (120 kWh/year) = 4-5 € yearly savings.