Our Kenmore 363-9554720 kitchen refrigerator “runs all the time.” Since this is a standard no frills side-by-side kitchen fridge, could it be inefficient enough to justify replacing with a new one?
The label indicates R134a coolant and 115VAC 60HZ 11.6A rating (USA), without indication of actual manufacturing date. Measuring the interior, the capacity is roughly 22ft^3. Appliance411 provides a date code search and estimates the fridge was manufactured “January of 1996 or 2006.”
The fridge was pulled away from the wall two feet and a Kill-A-Watt meter added. After 140 hrs, the fridge had consumed 17.99 kWh. Which includes measurements from weekdays, grocery day, and the weekend. Averaged, this is 3.08 kWh / day and extrapolated, this is 93.87 kWh / mo and 1,126.43 kWh / yr.
Wondering if having the fridge away from the wall improved the circulation and efficiency, the test was repeated with the fridge against the wall. After 152 hrs, the fridge consumed 18.68 kWh or 2.95 kWh /day or 4% less. The 4% decline could be explained away by the slightly lower temperature the second week. The label states minimum clearances are top=1.0in, back=1.0in, and sides=0.63in. Creating additional space does not appear to significantly impact performance.
The table below contains other Kill-A-Watt recorded measurements. Some of the measurements might not agree completely due to fluctuations and not being able to record all the values at once. The 160W of power consumed by the interior lights is surprising, and a failed door switch, leaving the lights on constantly would be painful.
|doors open, compressor off||1.32||160||160||1.00|
|doors open, compressor on||3.01||356||366||0.97|
|doors closed, compressor on||0.75||195||212||0.90|
|doors closed, compressor off||0.03||0.03||0.03||0.92|
With the compressor drawing 195W, 128.5 W/hr consumed, the fridge does run 66% of the day, so it’s easy to see why we might say the fridge “runs all the time.” Given our electrical rate and monthly charge, the fridge, consuming 94 kWh / mo represents roughly 10% of our electrical load, or $120 / yr. The EPA lists the most efficient appliances on their EnergyStar site, and most are expensive. Even if a new fridge reduced annual costs to $0, the cost would be recouped in 10 to 20 years, and with an average expected life of 15 yrs, there’s no benefit. That’s ignoring the waste of replacing a working appliance. We’ll keep the old fridge until it dies. When we do purchase a new fridge, we will look for one without an ice maker, a bottom mounted chest freezer, and ideally top mounted coils. Those features would seem to result in the most efficient fridge, energy and space.
Perhaps in a few months these tests will be repeated, prior to and after cleaning the coils. This service item is likely frequently overlooked, and fridges designed could be improved to ease coil cleaning, but what impact do dirty coils have on the efficiency?