But first, how does a refrigerator work?

The refrigerator is regularly switched on and off. With old refrigerators you can hear very clearly when the refrigerator switches on and off. What you hear is a pump to compress gas, after which the gas is then released. The process of releasing gas causes it to get cold. This cold gas is led through narrow pipes through the fridge along the walls to cool your fridge. This gas then returns to the pump to compress that gas again. This cycle repeats itself endlessly.

How do I recognize my refrigerator in the graph?

With the mobile App of SEM-1000 you recognize your refrigerator by a repeating square wave pattern when you set the range of the real-time graph to 12 hours or more. If you have recognized it, lower the range to, for example, 4 hours, so that you can see the entire square wave. Make sure you do not switch on any other devices for the next 8 hours.

What is a Duty Cycle?

Every time you open the refrigerator, the cool air flows out through the bottom and the warm air flows in through the top. This means that the refrigerator has to work extra to cool down to the set temperature again. Switching the refrigerator on and off is displayed as a duty cycle and expressed as a percentage (see the graph above). Duty Cycle simply means how long (t1) a device is on within a cycle (period T or t1 + t2). This allows the effective power of the refrigerator to be calculated. In this case the Duty Cycle of 48.48% times 131 watts of the pump, delivers an effective power of 64 watts. The goal is to ensure that this percentage is kept as low as possible. So, by not keeping your fridge open unnecessarily for a long time, you are already saving money.

Watch a demo video below on how you can measure a refrigerator with an app.

SEM-1000 (Smart Energy Manager for Smart Meter)

How can I see if my refrigerator is economical?

How can I save on my energy bill?