Home refrigerators represent a significant fraction of domestic electricity consumption. It is therefore important to be able to estimate and compare the power use of various brands, makes and models.
So how many watts does a refrigerator use?
The wattage of an individual refrigerator can vary wildly from model to model, and as such it is always best to find the specific information for the make and model of the device you are using (or considering), however as a rule of thumb we have prepared the following list of estimated power uses –
1940-60s era, basic unit, average size – 400 kWh per year (approx 140 Watt)1960-70s era, early frost free type, average size – 1700 kWh per year (approx 600 Watt)1980-90s era, average size single door – 1150 kWh per year ( approx 400 Watt)1980s-90s era, large size double door – 1700 kWh per year (approx 600 watt)Modern era, average size single door, “energy star” unit – 400 kWh per year (approx 140 Watt)Modern era, large size double door with ice maker, “energy star” unit – 600 kWh per year (approx 210 Watt)
As we can see the average family will quickly benefit from upgrading typical twenty year old refrigerator to a modern unit; typical electricity prices can range wildly so it is difficult to pinpoint the exact savings, but at 20 US cents per kWh (typical of the United Kingdom, expensive but realistic in the United States, cheap but possible in Australia, outrageously expensive in Canada) the saving would be in the vicinity of $150 US per year.
If your device shows only a wattage, it is still possible to estimate the usage in kilowatt hours. Although refrigerators are “always on” devices, the refrigeration units are designed to power themselves on and off as required to maintain the target temperature. A standard rule of thumb for estimating the unit’s active time is to divide by three; that is to say, for every day of operation, assume eight hours of power use.
So, To convert these wattages into a daily use of kilowatt hours (kWh – the standard billing unit of electricity suppliers), the following equation applies –
(Wattage x eight) ÷ 1000 = kWh per day
Where eight represents our presumed eight hours active time per day. Thus a 600 Watt unit – typical of older, larger refrigerators – would use 4.8 kilowatt hours daily, or 1750 per year; where a more modern 140 watt unit uses about 1.1 kWh daily, or approximately 400 per year. This is how many watts does a refrigerator use.