How many hours does a refrigerator operate in a day?

Answer 1

This is difficult to answer, because it depends on many factors -- how often the door is opened, the ambient temperature, how much is in the refrigerator, and whether new items were recently added to the refrigerator and need to be cooled down.

Most frost-free refrigerators have a timer that runs them for 6 hours, then defrosts them for 30-35 minutes. This means, at the the upper limit a refrigerator might run 24 hours out of every 26 hours, or an equivalent of 22.1 hours per day. (The timer only runs when the compressor runs on energy saving models, so if the compressor motor doesn't run continuously, the intervals between defrost periods will be longer than 6 hours.)

Once the contents are cooled down, a modern refrigerator in good condition might be expected to run 27% to 37% of the time at an ambient temperature of 70°F, i.e., 6.5 to 8.9 hours per day, and 45% to 61% of the time at an ambient temperature of 90°°F, i.e., 10.8 to 14.6 hours per day.

The only practical way to determine how long a refrigerator runs each day is to connect a run-time counter to the compressor motor circuit and operate the refrigerator for one to two weeks, or longer, then read the total run time from the counter and calculate the average number of hours the refrigerator ran each day.

Answer 2

A kitchen fridge uses about half a unit per day.